Video Games have a tendency to be hard. Thankfully (and contrary to popular belief) game developers would rather they be fun. One area in which players tend to suffer is finding items on the screen, especially if a game is all in brown palettes, scaled to realistic proportions, or full of so many dang colors/foliage/visual distractions.
So, when they have to make games more intuitive and help a player find Plot Coupons, health boosters, ammo, doors, mission objectives, conspicuously clickablepieces of junk, important NPCs, (big breath) or Interchangeable Antimatter Keys, they have to get creative to make them easily found.
In some cases, Notice This reflects situations where the character is more likely to notice certain objects than the player is, due to heightened senses, specialized training or simply being closer to the action in some game engines, making these uses of the trope somewhat of Gameplay and Story Integration.
Note that usually, good game designers will always have a subtle kind of Notice This going on in their design—it is beneficial to create distinct silhouettes, shapes, color schemes, movement patterns, sounds and so on so that the player can piece together what's going on more easily, especially important in parts that are fast-paced and require quick reaction times to clear. This trope is when the game designers cease to be subtle.
Commonly, developers will make these items more noticeable by:
The God Of War games mark interactive parts of the stage and scenery with a blinking point of light. It's small so as to not get in the way, but it's definitely noticeable.
In the sequel, stuff you can destroy is shiny.
Psychonauts has interactable objects glow with an aqua blue aura or sparkle silvery.
You'll know when you can dig up an Arrowhead when Raz is looking at the purple smoke.
This trope is the only way to find Deep Arrowheads. You can only dig them up when the Dowsing Rod is out and the higher the sound it makes, the easier it is to pull one up.
If your computer is good enough to run it on the highest settings, there's also a distortion effect around the tip of the Dowsing Rod that increases along with the sound. When it's making things nigh-impossible to see, you're right on top of one.
The original five Tomb Raider games made key items far larger than they would probably realistically be, Legend and Anniversary have them large and glowing (and in all the games, Lara occasionally looks in the direction of important items).
In Grim Fandango, Manny will look at any object you can interact with.
Escape From Monkey Island, which uses the same engine, adds a line of sight to make it easier to determine what Guybrush is looking at, something players often wish they'd had in Grim Fandango.
Items and item expansions in the Metroid Prime series make a mechanical humming noise; the hum gets louder as you approach. Also, if you use the Scan Visor, anything you can scan or otherwise interact with is highlighted in either red or blue (if you haven't scanned it) or green (if you have). (The first game uses orange and red icons that serve the same purpose and turn semitransparent once scanned.)
In Metroid Prime 3, objects that can be moved or torn away with the Grapple Lasso have a distinctive shimmer to them; once scanned, the visor also superimposes a semitransparent grapple icon over them.
The obscure, but good Horror action-adventure game Veil Of Darkness normal settings can be a pixel hunt (especially for the crowbar that's almost the same color as the floor), but it has an option to invoke the trope.
Sly Cooper puts blue sparkles on any items Sly can interact with. When playing as other characters, the sparkles change to their personal color - usually the same as the main color of their skin or costume. Justified by Bentley saying this is how Sly perceives his thiefly instincts at work. Other Notice This markers are stated to be part of a HUD on the characters' goggles/masks.
In the N64 Zelda games Navi / Tatl will flit to any important area nearby, often turning a different color depending on what sort of item/action is required. For example, if she flits above you and turns green, it means you can summon a scarecrow to use as a hookshot anchor.
The Zelda games will also occasionally take control of the camera to pan from you to the item you need to collect.
Speaking of Navi, this trope can backfire. There are times Navi flits off to a location that the player KNOWS doesn't mean anything. No item or song in the game will make anything happen.
That is an iffy one, a lot of quote "useless" unquote locations are very often either Scarecrow spots (Which require a custom song) or a randomized song (Most often Song of Storms) has to be played for a fairy fountain.
In the later games, if the camera is to Link's face, he'll occasionally look at something to the side. Occasionally, there is an enemy hidden where he's looking. This can range from turning his head, to just simply moving his eyes in that direction.
In Mirror's Edge, things such as pipes, boxes usable as springboards, and ramps are highlighted in bright red, called "Runner Vision". It also highlights doors in red that you can go through, and guards you have to pass (instead of avoid).
It does not, however, change the color of all doors, some of which are red by default and cannot be opened. And on Hard mode and time trials, Runner Vision is disabled.
In Shadow Complex, the flashlight will make destructible things glow different colors according to what can destroy them.
In Okami, a variety of things are used, including Issun hopping in front of something whilst glowing yellow (as opposed to his usual green), an item sparkling (or having a strange haze around it, as in the case of keys), and the camera suddenly changing to a fixed angle (often indicating the need to use the Celestial Brush).
In Tomb Raider: Underworld, there's a distinctive "jingle" sound effect when Lara is near a treasure or a relic. The sound only plays the first time she approaches it, though. In the previous game, Tomb Raider: Legend, Objects that the grapple can be used on shimmer.
Castlevania Symphony Of The Night features the Imp familiar suddenly taking interest in two breakable walls/pushable levers. "What does THIS switch do?!" The hundreds of other secrets in the castle don't seem to catch his interest.
At least two of the other familiars give reactions to hidden rooms. The fairy will float near a wall and tell you that there's something funny about it. The sword, on the other hand, skips the small talk and breaks the wall down for you.
In Pickory, one of the "secret" items has giant arrows pointing to it that say SECRET HERE.
In Grand Theft Auto, weapons glow and float in the air, and collectibles glow as well.
In Cave Story, any item you can pick up but is not visible right away is marked with sparkles.
It requires active purchase and equipping by the player (literal purchase, as it's only available as part of a DLC pack), but Brütal Legend features an item called the Oculus of the Lost, which swivels to stare at a collectible (Bound Serpent, Legend, Vista, Plug Jump) that the player missed when they get within a particular (fairly large) range.
Every Sierra adventure game ever. The most memorable example being: at the beginning of Kings Quest VI Heir Today Gone Tomorrow, you can see Alexander's tiny signet ring in the sand only because it's really sparkly and animated.
The Police Quest series is less forgiving, requiring you to (for example) figure out that that mess of pixels is actually a footprint and act accordingly.
King's Quest V: Absence Makes the Heart Go Yonder uses the "sparkly" method several times (a coin on the street, a locket in a giant bird's nest etc.). It's one of the incredibly few times the game is somewhat forgiving (of course, missing them anyway will ultimately result in you being stuck forever and the game being Unwinnable).
In the various LEGO games, any objects that can be collected, destroyed, or otherwise interacted with are appropriately made of LEGO pieces, while the rest of the background is a standard non-LEGO environment.
L.A. Noire features a detective mechanic whereby Cole Phelps examines crime scenes for clues. When you navigate him close enough to items that can be picked up and given a closer look (some of which turn out to be Red Herrings), the controller vibrates, and a two-note piano chime plays on the soundtrack. This effect can be disabled. It can also be enhanced, as the player has the option of spending earned "Intuition Points" to highlight the locations of all of the important crime scene clues in the map section of the HUD.
Some Jak and Daxter games will mark your next MacGuffin or checkpoint with a pillar of light that goes all the way to the sky. Notice This, indeed.
First Person Shooter
Some objectives (documents to collect, places to plant explosives, weapons in the tutorial levels, etc.) in the Call of Duty games glow golden.
While playtesting Episode Two, the developers realised that players kept losing their car. To help players notice it they made the car's hazard lights flash when the player leaves the car and eventually resorted to adding a compass that points to the car to the player's HUD.
The commentary for Episode One mentions that play testers were not noticing a scripted scene in the Citadel which took place in the opposite direction the players were supposed to head. In order to draw attention to this, the devs added a small platform with a single soldier who would begin firing at you. The soldier was far enough away that he's essentially harmless, but players would turn around to fire at the soldier and then see the scripted event.
A more subtle example is the use of coloured lighting: open, outdoor areas are often dark or lit with a cold blue light, while the path to the next area or a saferoom with item pickups will usually have a normal-sized doorway (or clean-edged hole of some kind) with warm orange light, to encourage the player to investigate it.
In BioShock, items like ammo and medkits are noticeably shinier than the environment around them. Particularly important items are highlighted in sparkly gold. The player can turn the shininess off for added difficulty and immersion.
Items in the Left 4 Dead have a blue halo around them, as well as displaying a pickup prompt when you approach them early in the campaign. In realism mode, these are disabled, but even then the characters will often clue the others in on their finds ("Pills here!"), and if you keep your crosshair on the item for a few seconds, they will start pointing at it with their hands.
Left 4 Dead, with it's low key setup, often uses lighting cues to direct attention to places you're supposed to go. They use car headlights a lot. This is a great solution because with few other light sources competing, the low-angle headlights are bound to be eye catching. And as a bonus, abandoned cars with headlights still on fit really well into the atmosphere of the game.
The safe room doors also glow. If you're on your last "life" (got downed twice, the third one will result in death), items and the safe door are displayed in red, probably trying to tell you to find a med kit and heal up. The game tells you how to do certain commands the first time you encounter them (item pick ups, healing others, etc.) but will stop displaying them once you manage to do these several times on your own.
The Witch in Left 4 Dead glows bright red in the dark — which is definitely a good thing, as shining a flashlight on her... well, let's just say it's a bad idea, to the point that most players will turn their lights off if they hear so much as a sob. Valve discussed this in the commentary. Every boss zombie and each survivor is designed to have a very distinct shape and sound so they can be identified quickly. Picking off priority targets first is half the challenge of Left 4 Dead. The Witch was designed be noticed, but not always easy to spot, since you're supposed to shut off your light. Valve wanted to add in a change of pace stealth element with the Witch.
The fundamental reason for the cartoony art style of Team Fortress 2 is to make the classes, teams and weapons as distinctive from each other (and from the background) as possible. In a realistic game, like say, Counter-Strike, you can't easily distinguish one soldier from the other, because soldiers wear uniforms and uniforms are well... uniform. The cartoony style gives TF2 the freedom to do whatever they want to let you know about important events and objects at a glance. It also lets them get away with outrageous humour and politically incorrect characters.
A semi-recent update added a glowing team-coloured outline around the Payload Cart and the Intelligence briefcase that also can be seen through any obstacle, so now, no matter where you are on the map, you know exactly where they are.
From launch, the Capture the Flag mode also added arrows to the Heads Up Display pointing to each team's Intelligence, whether it's safe, being captured, or dropped, and if you're holding said Intelligence, the direction of your home base.
NetBat in the Battlefield series, based on real-life network-centric operations, is a means of putting icons on everything. In Battlefield's case, these would be the red diamonds/lozenges on enemies, and green circles on friendlies. Similar systems appear in other realistic FPSes, like SOCOM and Tom Clancy's Ghost Recon.
According to Portal's in-game commentary, the developers tried to design a level that required the player to reuse one of the Weighted Storage Cubes. But players kept leaving it behind, not realizing they would need it for later. So the developers gave it a different texture, had GLaDOS tell the player they needed it, and the Companion Cube was born.
Portal includes many instances of this trope. Another example is the level where the player first acquires the Aperture Science Hand-Held Portal Device. Chell is forced to wait in front of a closed door next to a window through which the portal gun can be seen (and heard via its self-charging noise), to ensure that it's noticed. The excuse is that GLaDOS needs to acquaint Chell with the possible side-effects of the Aperture Science Material Emancipation Grill.
The developers also said on the commentary about the portal gun that they had to find a way to tell players what portals do without straight out telling them. They say that they added in a few levels before you acquire the gun, in order for players to grasp the concept of "go in one, walk out the other", seeing as how many of the test players found themselves believing that the portals sent them to different versions of a room or "auto warped" you somewhere. In actuality, the portals work on a basis of "what goes in must come out".
The commentary also notes how, when playing the "falling rooms" (where you must use falling to get flung forward), most test players thought that going through a portal while falling would cause you to go back to normal speed. For this reason, they added in the advice that GLaDOS gives.
"Momentum, a function of mass and velocity, is conserved between portals. In layman's terms: speedy thing goes in, speedy thing comes out."
Portal 2 has a part in the final confrontation in which the player has to fire a portal onto the surface of the Moon, which as just been revealed in the night sky thanks to the roof of the room getting a hole in it. The developers on the commentary noted how players would either not realize that there was a hole in the roof, or if they did, they didn't think of shooting the portal gun. For this reason, they made the camera automatically turn itself upwards towards the hole to give an indication to players that it was meant to be used for something. They however also faced another problem: due to how players had become used to instantly appearing portals, they still expected the portal to appear instantly, even though due to the speed of light and how far the moon is away from the Earth it would take at least a few seconds before it appears. Many test players ended up thinking that the portal could not be placed as it did not appear instantly. So the developers ended up locking the player's view once they had successfully made the shot to solve this problem.
Reality Bytes' all-but-unknown shooter Sensory Overload had a text window that would announce nearby objects as you walked past, punctuated with an audible "Wow!"
In Die Hard Vendetta, a little-known FPS, any new objects picked up will have a "You have the [object name]" message.
Weapons that can be dual-wielded (Revolver, 9MM, Submachine Gun, and the Tactical SMG, for some reason) will display the same message upon a second of those guns being picked up, considering how it's the same gun, only now you can fire two at a time.
Duke Nukem Forever will make the next objective glow bright yellow, whether it's the door you need to breach, the turret you need to man, etc.
In the first two Descent games, the powerups were represented with 2D sprite animations that were completely visible, even in pitch darkness. In Descent 3, they were replaced with 3D models that weren't as easy to spot. To compensate, the powerups now had a glowing "halo" effect on them to make them noticeable. Nearby shield orbs and energy sparkles will also make noise in D3 to make locating them a little easier.
Interactive Movie Game
This happens in the iOS port of Brain Dead 13 when the move guide allows the player to quickly press the appropriate button as soon as it lights up in certain areas, helping you to guide Lance in the right direction, as long as the move guide is turned on. However, it still counts as a Guide Dang It if you press a lit button that turns out to be a wrong move, especially in The Maze and in certain boss battles that make the game Unwinnable by Design if you run away from them.
Rayman Advance marked spots that triggered events with twinkling stars.
When Kirby encounters Meta Knight, there is always a sword that falls from the ceiling that you can touch to receive the Sword ability. As if, you know, a sword falling from the sky isn't unusual enough, there will also always be a giant blinking label reading "GET IT!" or "GRAB THIS!" with an arrow pointing to the sword. Yeah, designed for a younger audience, but still.
Sparkles in Glider PRO, though sometimes just for show, often indicated an otherwise invisible bonus, switch or transport.
Red Faction: Guerrilla highlights scrap with a prominent shine that moves in a synchronised wave from left to right. The effect can be jarring: target arrows look like HUD symbols, but this is "in-world". Fallen guns are also highlighted this way.
In the Wii A Boy and His Blob, any pathway covered in fireflies (Or their Bloblonian equivalent, fluttery rainbow... thingamabobs) is very, very likely to have a treasure chest at the end.
In Mega Man And Bass, some of the CDs are hidden underground and must be uncovered with the Rush Search. If the player is playing as Mega Man and has the CD Finder item, stars will briefly appear to indicate where they are located.
In Mega Man 7, using Rush Search may lead to him barking at seemingly nothing, indicating hidden items of great value or secret passages.
Role Playing Game
In City of Heroes, relevant items or objectives in a mission will both glow and emit a pulsing noise to indicate that it is nearby. This means that occasionally, when the object is well-hidden enough that the glow isn't visible, players will find themselves in the position of listening for crates of drugs and so on.
Some games have the habit of showing the name of every single usable item on the ground. Players of the Diablo series will know how annoying this gets when you kill a particularly generous boss.
The first Diablo didn't do this, and items on the floor were otherwise unremarkable and only highlighted when the mouse hovered over them. Now imagine rings and amulets, which have a "on-floor" graphic that's a blue ring a couple of pixels across. On a blue floor. In a dark dungeon. While the unofficial expansion added a spell which highlighted every lost item on the floor, and there was a built-in zoom function in the game, cooperative multiplay could (and often did) degenerate into the equivalent of searching for a dropped contact lens whenever that distinctive "ding!" was heard.
MegaTraveller 2: Quest for the Ancients. When you entered an area, the NPC characters worth interacting with were colored differently from the filler characters.
In the later Rune Factory games, any item, person or monster you can interact with will have an indicator hovering above it. Extremely useful when giving gifts, since the indicator shows who receives it (and none shows if you would drop the gift on the ground)
Vampire: The Masquerade - Bloodlines offers a gameplay implementation of how observant a character is, often highlighting an intractable object (with poly-chromatic floating particles) only if the relevant stats are high enough. In addition, the Auspex power makes the character more observant for a spell.
In the DS remake of Final Fantasy IV, Augments appear as golden sparklies on the ground.
Those same sparklies appear to mark items hidden on the ground in the Final Fantasy III remake, but only if you zoom the camera in really close.
Also present in the DS titles of Square Enix's other flagship series: Dragon Quest. Notable in that certain items hidden and marked in this way were originally marked on the NES or SNES by way of signs pointing to them or dogs guarding their spots; these original hints still remain in the DS versions.
Final Fantasy IX uses this by having an icon "!" appear over the character's head whenever he approaches a treasure or trigger. This is immensely helpful to the player when the character is "off in the distance" where perspective makes everything ridiculously small, or when triggers are part of the natural landscape, or when chests blend in with the environment.
Final Fantasy XII had the "!" icon and a ding noise as well, which was handy for chests you might've missed because the camera angle was wrong or they were behind a tree. It also had items lying on the ground glint if you were nearby.
In a particularly ludicrous example from Skies Of Arcadia, while in the Valuan sewers, if you investigate a certain patch of wall, Vyse will wonder if there's something about this bit of wall that's different from the rest, before dismissing it as his imagination. The "nothing" he dismisses? A patch of wall whose coloration is not unlike that of a patch of wall that has had the picture removed for the first time in a decade. Not long after, Vyse learns what the player has known since they first laid eyes on the wall: there's a secret passage behind it.
Baldur's Gate II lights up all dropped items and lootable areas if you hold down the Tab key. The first game didn't have this at all, which meant lots of pixel-hunting, even for common stuff like looting the bodies after a random encounter.
You can, with the help of the internet, play the first game on the second game's engine. Doing so will let you find things that you were meant to Pixel Hunt for, like the very valuable (by early game standards) diamond two screens out of Candlekeep. Or the Ring of Wizardry on the third map.
The Shadow Hearts games put an exclamation point over the main character's head when he's near an (otherwise invisible) item on the ground.
In The Elder Scrolls IV Oblivion, the crosshair changes its shape when aimed at something you can interact with; e.g. a hand-shaped reticle means the item it's pointed at can be picked up.
The color also changes if it would be illegal to interact with it (e.g. stealing owned property or breaking into a house).
In an audio version of this trope, when you are near a Nirnroot, you will hear a little tinkling sound, like faint bells. It gets louder the closer you get to it.
The Elder Scrolls V Skyrim tends to avoid this for the most part, but Nirnroot plants still glow and emit a sound a bit like a metal tube that's been struck, except the ringing doesn't die off.
Unfortunately, the glowing path sometimes takes a while to load, making you think you just left the area you were supposed to find in a previous screen, backtracking, and then finding out the game is just having trouble figuring out what it's really trying to do.
The first Fable also has items you can examine glow blue when you get near them, and people important for sidequests appear as green dots on the mini-map (and glow green when you get near them).
World of Warcraft uses sparkles to indicate slain enemies that still have items on them. The same sparkles were added to many quest item pickups to make them easier to see, aswell as herbs and veins if you are able to gather these. In addition, all characters are able to track most vital NPCs, seeing them indicated on the minimap. In some cases with larger view distances, large red arrows are also used.
Pressing the tab key in Neverwinter Nights causes every interactive object onscreen to glow and display its name. This is very handy when you walk into a storage room and want to know which crates might be holding useful items and which crates are just window dressing. Also, the toolset contains a lot of visual effects — sparkles, beams of light, and so on — that can be superimposed over any object you want to be conspicuous in your module.
The Infinity Engine D&D games (Icewind Dale 2, Baldur's Gate) did something very similar with the left alt key, highlight dropped loot, door and containers. A loading screen tip recommended keeping one's left pinky over the key while exploring and pressing it whenever nothing else was happening. There were also a handful of secret stashes that were flagged not to light up this way, the only clue to their existence being the mouse cursor changing to the 'loot' icon if you happened to cross the couple-pixel hotspot.
Dragon Age: Origins lets you hold down a key to make every item you can interact with glow, sparkle, and display its name.
In Earth Eternal objects you have to pick up or interact with as part of a quest are surrounded by floating sparks. The same sparks appear around the bag some slain foes leave behind, indicating that you can click it to 'loot the corpse'.
In Neosteam the position of your quest objective is indicated by a pillar of light.
In The Legend of Dragoon, a yellow icon with an exclamation mark pops up above the main character's head when he's near something he can interact with, like a treasure chest or an elevator.
In Gothic, interactive items will highlight and display their names when the protagonist is close enough to interact with them.
Deus Ex averts this fairly well, with pretty much everything being properly scaled, tucked away in the shadows, laying flat and unmoving on shelves, matte instead of shiny or glowing (except for the augmentation cannisters), and so on, to encourage the player to explore everything. Objects do however stand out from the background as a result of bold color use (required because of the game's 2000 era graphics) and mostly flat surfaces (While Unreal Engine 1 can do terrain to some degree, it's an utter pain as, like even modern FPS engines, the basic shapes for the editor are boxes and straight lines, it helps that the game is largely in developed areas), but the appearance is overall a "natural" feel.
Surprisingly, even the Dragon Tooth Sword, which glows blue, is found in a brightly lit area being glass that makes it harder to see.
Any item you can pick up/use does get pointed out by your character's HUD if you get close enough, fortunately. It is also justified in-game, in that the character has an implant in his eye to give him a targeting reticle, among other things.
Deus Ex Human Revolution on the other hand has all interact-able objects highlighted with glowing yellow, including breakable walls that would be quite hard to notice otherwise.
Justified in that case, because of the limited color palette of the game. The graphics have a distinct yellow tint throughout almost the whole game which makes it incredibly hard to notice small objects. The breakable walls are only shown by a few cracks in the wall aside from the highlight, which makes them borderline impossible to see. However, the game does offer the option to turn the object highlighting off, which pleased the more critical fans of the original game.
Crisis Core uses either a dialogue window or a small glow for objects you need to collect on some side missions.
Fallout 3 mostly averts this, and sifting through wreckage to find a syringe full of Med-X among empty syringes or plasma rifle ammunition among shot glasses in the game's (many) ruins can be tough... but the Operation: Anchorage downloadable content expansion lets you into a military simulation where this is used to the point of being lampshaded, with anything in the simulation you'd want to pick up pulsing with a bright red glow.
Fallout New Vegas has companions provide you with a perk while they are in your service. Boone's "Spotter" perk will highlight enemies in a red glow when you zoom in with your weapon. Rex's "Search and Mark" perk highlights containers/corpses that have weapons, ammo, chems, or caps when you zoom in with your weapon.
Pokemon both subverts and plays this trope straight. Items found on the ground use a Poké Ball sprite (usually called an item ball), but quite a few items aren't represented at all, or are found in scenery. Some of the latter cases are easy to spot (such as being located under a rock in a cave or within a patch of tall grass on a square without tall grass in outdoor areas), while the rest rely on an item specifically for finding them, called the Itemfinder in the first three generations' English translations and the Dowsing Machine in the Japanese versions and the English translations of Generation IV and on.
A strange in-universe example in The Witcher 2. Objects you can pick up and doors you can open usually look just like everything else, but activating your witcher amulet makes them glow orange and wiggle a bit. The amulet's purpose in the story is as a sort of Everything Sensor that points out magic and other important things.
Pandora's Tower shows anything Aeron can pick up as a flashing sparkle, white for sundry goods, red for books and texts. The manual actually uses this trope indirectly to explain why Aeron can occasionally find new things in the Observatory's cellar despite being the only one who goes down there: there's so much miscellaneous junk crammed down there that another perusal with fresh eyes is sometimes enough to spot something useful he previously overlooked.
Chrono Trigger: Tabs (consumables that gave your character a permanent stat boost) sparkle if they are laying around on the floor not in a box.
At one point, you pick up such a shiny, only to be told to put it back because it's not ready yet.
Need for Speed: Most Wanted flashes the screen and pans the camera towards the fuzz every time you're spotted.
It's REALLY COOL.
Carbon also has scout teammates that highlight the course's shortcuts by taking them while leaving glowing tire marks.
And even if you miss THAT, the path is also marked on your minimap. But then again, that's the whole point of a scout teammate...
In FUEL, whose whole premise was its huge open world, interesting objects like car wrecks were often many kilometres away behind the horizon. How does the game point them out? With smoke signals where possible, with a giant red laser beam from the sky where not.
In Assassin's Creed, all flags, city guards and (after you get the throwing knives) random thugs that you can pickpocket are highlighted with Animus-powered Matrix Raining Code to show that they're important.
In addition there's the "Eagle Vision" mechanic in which you can switch to first-person-mode, and targets, guards, friendlies, and regular people will glow specific colors for a while. This is very handy when trying to find a specific target in a crowd of people who all look exactly the same.
The sequels modify Eagle Vision the player can use it while moving, and during trailing missions the target leaves a golden trail that makes it that much easier.
In Last Ninja 2, if you find a map, from now on all collectible items will blink the first time you enter a screen.
In Thief Deadly Shadows, lootable items glint and sparkle subtly every few seconds to differentiate them from normal stage props. In essence, the message is, "Steal me."
The previous games had differences in colors to signify value. For example, a white plate has no value and can only be picked up, not stolen. A decorated gold-colored plate is likely of some value. Deadly Shadows was disliked quite a bit by fans of the previous games for, among other things, this mechanic.
Batman Arkham Asylum features Detective Mode, which offers a visual representation of Bruce Wayne's remarkable detective intellect (as well as a device activating in his mask letting him see through walls) to the player by highlighting useful items in the environment (such as grates to pop open and gargoyles to climb onto) and showing enemy locations from behind barriers.
Arkham City has the same feature, and clarifies it as a combination of Wayne's detective skills and a collation of all the data his surveillance gadgetry is feeding into his cowl. By contrast, Catwoman has Thief Vision, which can only highlight enemies and her exclusive escape routes, which makes sense since she's relying on only her five senses.
It also makes the Riddler's informers glow green to set them apart from common thugs, so you know exactly the ones you shouldn't take out in order to interrogate them.
Resident Evil games have important items stand out through Sparkles. Hand waved in the official books in that they are well-used and thus cleaned items that show up against the filthy-un-used corridors, battle debris or blood-smeared walls.
In Silent Hill, beginning with Silent Hill 2's James Sunderland, the protagonists will turn their heads to look at anything that's collectible or interactive. Unfortunately, they also turn their heads to look at enemies and Death Traps.
Silent Hill: Shattered Memories doesn't have Harry looking at hotspots, but it does have the Shadow Girl, who will run in the direction you need to go when approached; this is extremely merciful on the developers' parts in some places, because indoors, the flashlight is your only light source, and without the Shadow Girl, the player is reduced to scouring the walls for subtle doors outside the flashlight's illumination. Also, when running around in the Nightmare, doors, climbable ledges, and fences are laced with gently glowing blue frost, so you can find your way even if you turn your flashlight off.
In PS2 games Clock Tower 3, Haunting Ground and Kuon, items appear as shining objects, much like the Resident Evil series. Kuon even throws in head-turning ala Silent Hill, though this is often misleading as apparently doors qualify for head-turning as much as items do.
In Obs Cure, items do nost stand out from regular pre-rendered graphics. Instead you rely on character Josh's special ability, which allows him to tell the player if there're any items left to pick up in the room you're currently in.
Parasite Eve 2 has an interesting and very subtle take on this - early in the game the main character "notices something", as noted in a small dialogue box... and a barely-perceptible flicker appears where that "something" is. If you don't know the flicker is there, you might not even realize why you're going in that direction.
In the Penumbra series, items that can be picked up glow when you get near. This can actually be turned off in the options to make the game more "challenging".
In the related Amnesia The Dark Descent, tinderboxes, key items and jars of lantern oil glow a soft blue when you're near them. When your hand hovers over them, the cursor changes to a hand picking something up, in contrast to the open hand when it's just a movable object.
In Dead Space ammo and pickup items pop up an impossible to miss hologram when you get near them. Important item also glow at a distance.
In Odium, markers pop up over interactive objects and exits when your characters get close to them, and important items flicker in and out.
In Rule of Rose all important items glisten with white light, but most don't become visible until your dog sniffs them out. A major exception are the ornamental knives held by some enemies that are needed to gain a secret weapon late in the game; there's absolutely no indication of what they are unless you look closely and see that they are gold-coloured, until the enemy drops them and they become ordinary items. Finding them is almost impossible without a guide, as they only appear during times you are normally supposed to avoid enemies instead of fighting them.