The Minus World in Super Mario Bros. and the Secret Worlds in Metroid are 'hidden' areas resulting from reading game code as level data. They can be far, far stranger than anything a human designer could have imagined. There are websites dedicated to exploring these strange wonderlands-that-were-never-meant-to-be!
Snowman's Land in Super Mario 64 has a bug in which, after Mario's hat is blown off by a gust of wind, warping between points in the level causes the hat to replicate. Not only was it possible to scatter hats all over the level, it was possible to get Mario to hold his hat in his hand rather than wearing it.
Notably, after doing the hat-in-hand glitch, any other object Mario picks up will not be visible; presumably because his hat is already occupying the hand's "held item" memory slot. When you try to throw the item, Mario does the motion but no item appears. You can then walk around the level a bit and suddenly see the object appear out of mid-air in the same state as it was when thrown. Each level that allows this glitch has a specific location where the thrown item will reappear. The reason why it appears out of midair is that the levels are also loaded and unloaded as Mario moves to save memory. If he's not in the area, objects are deactivated and temporarily cease to exist as far as the game is concerned. This can be viewed if you enter any level with a large field and some enemies, they clearly "blink into existence" as you approach, and will appear to have been "paused" in motion.
Both Super Mario 64 and the remake Super Mario 64 DS have glitches which allow you to skip huge portions of the game, in the former by a reverse version of the long jump mechanic, allowing Mario to go backwards fast enough to clip through locked doors and beat the endless staircase (0 Star runs are possible), the latter with some glitches allowing you to enter the basement with as few as zero Stars and beat Bowser as anyone with as little as fifty Stars (and completely screw up the credits in the process).
There's also the fact that the Hit Points meter becomes the air meter when Mario is under water, which creates the (probably unintended) ability to completely refill his life by diving into the nearest body of water that's deeper than Mario is tall. Your life points refill when you surface. (Later games use a separate oxygen meter instead, except for Super Mario 3D Land, which lacks drowning due to its nature as what Shigeru Miyamoto calls "a 3D Mario game that plays like a 2D Mario game.")
In Sonic the Hedgehog 2, there's also a point in Chemical Plant where you go so fast, the screen can't keep up.
This gets referenced in Sonic Generations, only in Chemical Plant can Sonic outrun the camera, it keeps up with him anywhere else.
You can do it in the very first level of Sonic Generations, Green Hill Zone.
Also achievable in Sonic Advance, early on in the very first zone. Stop after the spring, then spin dash into the two loops. The added speed will ensure that the camera can't keep up. Awesome.
This happens all the time in Sonic Advance 2, and the camera appears to go crazy but its actually quickly running over the ground you already ran.
Sonic Advanced 2 also had the Jump Dash trick, wherein if you jumped and quickly did Sonic's air-leap maneuver over and over with good timing, Sonic would EXPLODE off, leaving the screen in a matter of moments. This is abused to no end in Tool-Assisted Speedruns.
There is also a bug in Oil Ocean Zone in the beginning of act 2, if you jump at the side of the big purple platforms. you will shoot up into the sky. But if you get hit by the spikes and fall in the green ball-like tubes you'll fall out of them. If you've done this Sonic should be twice as fast and jump twice as high.
Another Sonic 2 example (though it has zero impact on gameplay, it's just a glitch people have taken to fondly) is the ability to garble Sonic's colour palette. Executed using debug mode, if you place a bunch of waterfall objects on Emerald Hill Zone, when you transform back to Sonic, he'll appear out from behind the waterfalls with a neon green hue with black spots around his head. This is called the "Ashura" glitch ("Ashura" is just a name fans made up for the now-green Sonic). The fandom likes this and has turned "Ashura" into a fanon character on the side, but the glitch itself is just a simple palette error generated by the debug mode.
Similar to the above Chemical Plant example, a staple in Sonic 3 and Knuckles The Speedrun technique is the "screen warp spin dash"; essentially, as most of the levels in the game wrap around onto itself, you can duck down until the screen scrolls down, then spin dash in place and jump. If you time it right, you'll get "lost" in the top of the screen, and the camera will rapidly scroll through the entire level in an attempt to find you again. Since sprite-based obstacles such as spikes and destructible walls are ignored when they're not onscreen, this can be used to skip to parts of the level you shouldn't be in. You can even use this trick as Sonic or Tails to warp to areas in a level only accessible to Knuckles.
Speaking of glitching out items that are offscreen, this can be abused to let Tails jump on spikes while playing in tandem as Sonic and Tails. It's the easiest to perform on Carnival Night Zone, where Tails can stand and jump on spikes as long as the spikes themselves are out of view, treating them as a basic platform and only hurting Tails when the screen scrolls down far enough to expose the spikes.
Sonic Adventure had a ton of clipping issues with its "Adventure Fields", enough that you could force virtually any character into almost any "Action Stage" in the game (most of which are off-limits to them, or have their own, unconnected part of the same level that no other character can gain access to).
Its sequel, on the other hand, features a stage at the end of the game consisting of 5 sections, one for each character except Shadow. Though the time switch gimmick in the stage stops the game's clock, your final time will usually be in the six to eight minute range (so about 15 minutes real time) if you haven't ever played the stage before. There is a glitch, however, that will enable you to finish the stage with a time lower than 10 seconds.
For anyone having trouble with Sonic's Casino stage in Sonic Adventure DX, get a player 2 controller, look at a monitor, which stops the time... And let Tails go into the place where you play Pinball, Sonic will then be pulled into to the pinball machine, which stops time, allowing players to complete the level around 5 seconds.
In Sonic 3 And Knuckles, one could skip almost the entire Sky Sanctuary when playing as Sonic, by finding a lightning shield, then crouching, and jumping into a certain pit, skipping the first two boss battles completely. The lightning shield is needed to complete the jump.
Some of the Sonic & Knuckles lock on cartridge content was already in Sonic 3. This could be discovered by accident in the some copies of the game by staying in the water in the Hydrocity Zone mini-boss fight until the drowning music played. Then leave the water and voila, S & K mini-boss music.
The kicker, of course, is that the initial music in Hydrocity Act 1 in Sonic 3 isn't the Sonic 3 miniboss music but the main boss music, which unlike the miniboss themes is used in both games as well as the locked-on version (as opposed to how Sonic 3 & Knuckles uses the miniboss theme from Sonic & Knuckles in that case). So it's a bug WITHIN a bug.
Sonic 3 features a musical glitch present on the file select screen, in which staying on said screen for about 47 minutes causes one of the instruments to increase in volume, creating an interesting musical variant. This doesn't happen when Sonic & Knuckles is locked on, though.
One particularly useful example would be one enabling Silver to use a crate to glitch through the last door in his Dusty Desert stage, which allows one to bypass the terribly annoying section which involves precisely moving around an ancient Egyptian giant billiard ball(!) by hitting it no more than 9 times to navigate it around numerous corners and holes in the ground. Just using one of the many crates around to pass the last portal is certainly the less painful option.
E-123 Omega's hovering ability can be exploited to reach basically any part of any stage he's playable in. If one rapidly taps the jump button in midair, the flight can be extended almost infinitely. Doing so however while pushing against invisible walls wil cause Omega to rise up high into the sky, eventually high enough to fly over all boundaries and explore any area of the current section one could imagine.
Click here to see an example of someone (unintentionally) abusing Omega's ridiculously buggy glide.
The entire physics engine used in the game is hilariously broken: you can topple a massive, fifteen-story tall tower built from solid rock by throwing a wooden box at it.
The fact that Sonic's ability meter never drains leads to endless possibilities: infinite electro barriers, endless boosting...the best uses, however, involve slowing time as much as you like (I'm looking at you, Radical Train!), infinite jumps, and scaling practically any wall.
The pause glitch in Mega Man 1, where rapidly tapping Select would cause continuous damage to enemies being hit, especially with the Thunder Beam. Due to the game being Nintendo Hard, this is exploited quite a bit.
Ladder physics also worked oddly in the first Mega Man games. Cue tool-assisted speedruns of Mega zipping up them so fast that the graphics stop loading properly.
In the first two games, this could also be used to slow the internal timer used for determining how long Mercy Invincibility would last, greatly extending its potential usefulness. Possible to trigger in the first game, but much easier in Mega Man 2 where the Quick Boomerang's rate of fire could reliably activate it.
In Mega Man 2, there is a glitch in Heat Man's level that will push you through walls. At one point in the level there is a long stretch of walls with disappearing blocks that you're intended to jump on to get over them. If you stand in the same place as one of these blocks as it appears, it will have one of three effects: 1: it will render you completely immobile until it disappears. 2: if you are standing to the left of center, it will push you to the left side of the block. 3: if you are to the right of center, the block will push you straight through the right hand wall to the other side. While this can be pretty handy, it also means that you could get pushed into a bottomless pit if you're not careful.
Additionally, the split-second morphing effect makes Mega Man invulnerable until his transformation to his selected weapon is complete, though this is a brief fraction of a second. A clever player can pause and unpause rapidly, maintaining him in a constant invulnerable flux state long enough for a weapon to fly through him with no ill effect whatsoever. Excellent for dealing with attacks that move too fast to be dodged.
In Mega Man 3, a glitch (bug? hidden code?) allowed Mega Man to never die. It involves holding Right on the D-pad of the second controller, then jumping into a pit. Mega Man will lose all his health, but he can then jump back out of the pit with zero health. He will be invulnerable to everything but spikes and more pits, but can't use his Mega Buster.
You can't be killed by HP depletion, but healing would likely kill you, since it gives back just enough HP to get killed by the next hit. You could also make use of the Arm Cannon by selecting the Rush Coil. You can fire as long as Rush is present.
It was also possible to get the Rush Marine and Rush Jet after beating Shadow Man. The Marine you get directly, while you could get the Jet by selecting the Shadow Blade and pressing Right, then picking up Weapon Energy. You could also get the Marine indirectly by the same method after beating Sparkman. This doesn't work in Mega Man Anniversary Collection, where the menus are single page, like Mega Man 4 on.
Another glitch allowed a high jump by jumping and shooting precisely simultaneously. Makes the Rush Coil completely useless.
In some of the games, if a weapon took more than one to eat up one pixel of weapon energy, you could use the weapon for free by using the weapon once, pausing, reselecting the weapon, and unpausing. This was highly useful for the last boss of 2, by conserving uses of Bubble Lead as you fought.
In Mega Man 7, it was possible to kill some bosses (like Turbo Man or Spring Man) by shooting Shade Man's weapon as you're entering the room. It will bounce off the walls and hit the boss as his HP is beginning to fill, causing an instant kill.
Kirby's Adventure has a puzzle in the third level of Orange Ocean that leads to a switch that will activate an event in the Hub Level; you're faced with a cannon, which has a fuse that you have to light. The only problem is that the fuse is underwater, which means that using fire is out. In concept, you're supposed to get the Laser ability from a Laser Ball just outside the room and then shoot a laser at the (slanted) ceiling above the fuse, which will light it. In execution, however, you can also inhale a Hothead, walk over to the fuse, and then swallow it, which makes the fire from the resulting Transformation Sequence light the fuse. This was fixed for Nightmare in Dream Land.
However, in Kirby Super Star, a certain treasure chest in The Great Cave Offensive can only be reached if you know to light a fuse this way, making it an Ascended Glitch as well (although you can also get a helper to light it for you).
In Citadel (a mid 1980s platform game by Superior Software for the BBC Micro), if you drop a trampoline in the room furthest to the right (the room where you find the hieroglyphic statuette), and use it to jump high enough to reach the top of the screen, you end up on the title screen.
Super Metroid has the incredible Murder Beam (also known as Space/Time Beam or Spazma Beam), a bug caused by activating the Spazer Beam and Plasma Beam simultaneously (needs pretty good reflexes or dextrous fingers). In most locations, firing this weapon will cause everything to slow down and fade to black as the game crashes. In some places, though, the game does not crash but just causes minor graphical glitches instead. This includes the final boss fight, where using it causes the boss to move slower, making the fight a bit easier. If you save after using the beam in a safe spot and reload, the game will be reset back to the very beginning, at the Space Colony. All upgrades (except missiles) are retained, however, allowing you to beat the crap out of the early bosses with weapons that kill them in one shot and obtain up to 900% completion.
What the Murder Beam does is that it creates a vertical wall of damage, and anything in the wall takes constant streams of damage. But the only way to fire it without crashing the game is by firing a charge shot Left. Since you have to fire once to start charging, you have to pause the game, hold the fire button, and unpause it to charge without firing an uncharged shot, and fire left. Since Mother Brain is the only boss in the game that consistently stays to the left of you, she's the only one it's really effective against.
The Murder and Space/Time Beams are not the same weapon. The Murder Beam has all five enabled, while the Space/Time beam only has the ice, spazer, and plasma beams enabled. The wave/spazer/plasma combo results in the Chainsaw Beam, which has an absolutely amazing rate of fire, but only affects beam-destroyable blocks (it can't hurt enemies). On another note, thanks to a variety of bugs, every boss in the game can be skipped:
Bomb Torizo: With exceptionally good timing (we're talking, every frame has to be spot on) it's possible to get out with the bombs before the door closes. In the PAL version it's easier and can even be done in realtime, but on NTSC versions you need tool-assistance. It's not possible without it.
Spore Spawn: The Super Missile pack from the beginning of Brinstar, which normally requires the Speed Booster, can be collected either by shoulder boosting, or using a well-timed Mockball. You can even return later to get the super missiles from it by doing a crystal flash in the tunnel you'd normally return from after you kill it.
The Mockball is a glitch that maintains running velocity while in morph ball form, which is usually limited to walking speed. If performing a running jump and performing a quarter-circle forward control pad sweep at the right moment can glitch out this limit. With the speed booster it is possible to perform this after the speed booster has executed for a Speed Ball.
Kraid: If timed correctly after the initial missile shot to the mouth, the player can switch to super missiles and pump three rapidly into Kraid during his damage animation. it is possible to kill him before he lifts out of the ground with this glitch.
Crocomire: The Grappling Beam is not necessary to beat the game, so neither is Crocomire.
Golden Torizo: The Screw Attack can be collected from the other end, albeit much later. You can even get it before the Space Jump, if you're absurdly good at performing the infinite bomb jump.
Botwoon: See below; it's not necessary to ever enter this part of Maridia. In fact, it's not necessary to enter Maridia at all.
The four main bosses: With a recently discovered door glitch, it's possible to enter Tourian without defeating them.
Mother Brain: The same glitch, used in a different way, skips the room with the Mother Brain and leads straight to the escape sequence. You don't have the Hyper Beam, but it's not necessary.
Metroid: Fusion has a bug with Golden Zebesians. These enemies cannot be damaged unless you shoot them in the back. However, the game determines whether you're shooting it in the back based on which direction both you and the Zebesian is facing. Hence, it's possible to damage them with charged shots to the front by turning away from them before the beam hits.
The freeware game N (which some may know better for its enhanced and bug-fixed console version N+ ) had a huge number of bugs which were so popular with the community that many were eventually embraced by the producers in later levelsets, and all were explored heavily in custom levels. This includes, among other things: At least a dozen ways of getting past any one-way walls whose placer hadn't been very careful about the nearby terrain, placing huge stacks of gold on top of mines or switches to delay their activation until all the gold was collected at a rate of one per frame, freezing moving enemies by starting them surrounded by doors, making floor sweepers fly, starting moving enemies inside a wall to allow them to move around inside it until they escaped, using the floating elastic cloud blocks to make superjumps, manually editing launchpads in the level editor to create one-way teleporters, and placing thwumps facing into a wall at just the right distance so that they would be immobile until you touched them, at which point they would slowly move backwards through walls until they left the level, acting as moving walls. Sadly, almost all were fixed in N+ , to the original creators' protests as well as the fans.
There is also the thwump cannon effect, where being between two thwumps moving in opposite directions somehow launches the ninja with a huge velocity.
And glitched tiles that would launch the player in random directions.
There is also a bug where if you hit a launchpad and a deadly object (rocket, drone, thwump, or floor sweeper) in the same frame, N gains the ability to phase through any object (unfortunately, this also includes the exit door).
In Blaster Master for the NES, certain enemies were susceptible to a easy to exploit glitch that would kill them without much effort. While the boss is flashing from taking damage, bringing up the inventory effectively paused the movement of the game but the boss would still be damaged as long as he was still flashing. Pausing in the PAL version led to more exploitable glitches, including a Double Jump.
In Dragon Ball Z: Buu's Fury, you can eat the Senzu bean before you give it to the person. Does this mean the game wants you to get another one? No! It takes the one you don't have, which gives you 255 Senzu Beans.
Super Mario Bros. 3 has an odd bug that had no explanation for years (until about 2005!) and got many gamers called crazy. The sound effects for tail-wagging and a one-up interacted in a way the developers did not anticipate. Because of the way the sound chip handles interrupts, attempting to play both at the same time results in playing the one-up sound, but reading in more data than it should. Because NES sound effects are written in reverse order, this results in a corrupted beginning, followed by the complete normal sound effect. Oddly, some people have remarked that the "extended version" sounds pretty cool. The effect can be observed here.
This video uses a hacked RAM to "extend" any sound effect.
Spyro the Dragon: Gateway To Glimmer and Year of the Dragon both had a few levels with the 'swimming' glitch - if you charged out of the water just so at certain points where the ground is level with the water, you can trick the game into letting you swim through the entire level. It makes finishing the stage a cinch and you can even finish a few of the challenges in a level by cheating, like swimming around collecting sprockets instead of riding a cart for them.
Spyro 2 (Ripto's Rage/Gateway to Glimmer) also had a fairly easy to pull off 'double jump' bug, which allows you to go many, many places you should not be going. Viewable here, and in many other places across YouTube, to impressive effect.
In Jak II: Renegade you start out with access to only part of Haven City and have to pick up passes to disable energy barriers to let you through. Until you get these, the barriers are there for everyone. So if you're near a barrier you haven't opened yet, and the Krimzon Guard are pissed off, you can see a KG jetbike slam into the glowy energy wall, crash and die. Another minor glitch is not as usable, but nevertheless creepy: Jak's reflection in the mirror behind the bar of the Hip Hog Heaven Saloon has horns. And then there's a glitch that causes all metallic textures to become bright, candy pink. It makes it seem Sig is out on a mission to prove Real Men Wear Pink, and the Metal Heads become decidedly less scary.
In Jak 3: Wastelander there's a bug that requires the Light shield and flight powers. Normally, the flight ability is more of a gliding power, only really slowing the speed and increasing the distance of falling. However, the shield power seems to suspend you in mid-air for a moment if used while jumping. So by activating Light Jak and then alternating between using the shield and flapping the wings given for flight, you can now achieve true flight. Enabling Infinite Light Jak allows you to fly anywhere.
Ratchet & Clank has a bug in the first game. Enter the first Hoverboard race wearing the robot disguise, and the other racers and the boards disappear, leaving Ratchet free to walk to a certain ramp, hit the Taunter, and wait as the boxes above break. And break. And break. It's basically possible to tape or weigh the O button down for a few hours and come back to be able to afford every weapon in the game.
In the same game, as well as the next two, it's possible to 'wallhack' with the Decoy Glove/the turrets and thus push yourself through walls and get places you aren't supposed to go. This is also possible in the fourth game, though pointless due to its 'arena combat' nature. Insomniac appeared to have wised up by the Future trilogy, as the turret-type weapons will only let you throw two at a time - wallhacking requires three turrets.
In 2 you can climb most walls by going up to them in first person, jumping, and then spamming your wrench at a downwards angle
However, it is possible to encounter a glitch in the Tools of Destruction that can prove useful: in the final level, about midway through, you have to ascend a grav-ramp in order to go inside a nearby building. However, if one approaches the grav-ramp just wrong, Ratchet will wind up falling through the level, and a little adjustment with the hover-pack can send him right to the outside of the Court of Azimuth, and the location of the final battle. This locks the door behind him and sends him into the final boss battle without requiring him to play the rest of the level. Which would cause you to miss out on a couple of goodies (a Gold Bolt and a RYNO IV holoplan), but if one restarts the level, they will find that the game things they cleared everything; all of the doors are open (including the Gold Bolt one), and all of the enemies are already dead, allowing you to pick up everything in the level at your leisure.
Tools of Destruction has another one with the Razor Claws. If you jump and use the claws, you normally speed down to the ground; but if you hit a wall, the game thinks you are on flat ground for a second, allowing another jump. Combine this with high jumps, and it's possible to get to the Court of Azimuth while it is still daytime. The glitch also allows you to get a few Gold Bolts without having to figure out the normal way to get up.
In LittleBigPlanet, someone somehow managed to create a 50-some layered object (despite sackboy only being able to interact with three layers), which, due to the very player-friendly mechanics of the level editor, allowed other players to make their own. The result was an unofficial background and foreground tool, which became quite popular. Media Molecule has (reportedly) several times attempted to remove it, but because of item sharing and the fact that anyone could create their own once they have one, they have been highly unsuccessful.
Also, it's something of an ascended glitch. When they released a pack of new items, for free, that were basically premade glitched version of existing items, like the infinite spawn which before could only been done by a trick with spawners, there were objects in those "forbidden" layers. To good effect, too.
There's a technique (also mercilessly abused by speed runners) that allows Donkey Kong to fly through the air with a carefully timed combination of attacks on sloped surfaces, dubbed the Moonkick. Although very tricky to pull off, it's possible for the player to enter Fungi Forest at the start of the game using this method. Behold!
It's also possible to fall through the stairs in the Troff n' Scoff areas (the gates to the level bosses, seen in one of the links above) and thus not have to collect any bananas at all... or fight a boss with the wrong character. Fighting Mad Jack with Chunky Kong (who spontaneously turns into Tiny Kong during the introduction cutscene)? It's possible.
You can avoid the difficult Bramble Race against Screech in the second game by exploiting a glitch at the start. If you come up right behind Screech to where the race will not start yet, and you fly upwards (you must have both characters at this point for this to work), you will then hit the the ceiling and hurt yourself causing yourself to blink. Quickly, while you are still blinking, pass Screech and head off to the rest of the level without having to worry about doing it in good time.
Rocket: Robot on Wheels has a pretty good physics engine, with one slight exception: The game includes cheat codes for things like lower gravity and higher strength, which the game wasn't necessarily programmed to deal with on a normal basis. Thus, by using both the Low Gravity and High Jump cheats, it is possible to jump outside the game world in the very first area and plummet into nothingness.
The Extra Strength cheat also has a habit of not playing nice. Picking up vehicles, in particular, tends to make the game do odd things. It tends to make player character Rocket "hop"—sometimes it's just a little bunny jump, but other times (seemingly at the whim of the Random Number God), Rocket will be catapulted into the air until he collides with the skybox. Letting go of your impromptu jet before getting there will let you descend quickly, while you get to watch a go-kart shaped like a hot dog gracefully bound across the landscape.
In La-Mulana, the trigger for the right side Mini-Boss of the Twin Labyrinths can be avoided with a well-timed jump, so it will just sit there and get killed.
In the original version of La-Mulana the player could time a jump through the far left door of the Infinite Corridor and have Lemeza stuck in the wall on the next screen. Continuing to jump causes Lemeza to "climb" the wall until he goes through the ceiling and ends up on the bottom floor of the area. This allows the player to completely bypass the third floor of the Corridor filled with the annoying block puzzles.
Yahtzee'sTwelve Thirteen has a final boss battle that involves running, climbing, and shooting the boss over and over again in a difficult pattern. Unless you shoot the boss once, pause the game with the projectile still intersecting the boss, then unpause several seconds later. Instant win. Might be a reference to the first Mega Man game, which had the same bug.
Banjo-Tooie has the Pack Jump, which allows Banjo to Double Jump during his Pack Whack attack. While not entirely game-breaking, it does allow quite a few shortcuts to areas.
In the "Funky" special stage, wait for the timer to reach below 100 seconds to cause the music to speed up. Then, eat a green berry to restore 20 seconds to the timer. If you keep doing this, the music will keep speeding up.
Yoshi can swallow a P-Switch right after it's been used, and then spit it out good as new. A tool assisted speedrun abuses this to have Yoshi continually eat and spit out things in such a way that it corrupts memory and runs the end credits in the middle of the stage.
In the old Spectrum / C64 game Stuntman Seymour, you had 4 lives indicated by the "Take #" indicated on a movie clapperboard at the bottom of the screen. It incremented by one as soon as you took a hit (so it was game over when it said "Take 5"). However, the game only checked for the presence of the number 5 immediately after taking a hit. Occasionally if you took a hit right as you killed the boss of the level, the counter would increment again as the level ended, meaning if you lost your penultimate life just as you killed the boss, it was possible to start the next level already on Take 5, effectively giving you infinite lives (the Take counter would go up to 9, then A-Z, then a-z, with some punctuation symbols in between. I can't remember if it eventually wrapped back round to 0, meaning that you could once again lose, but this would require you to die at least 255 times, so it may as well have been infinite). Certainly more than enough to get to see all the levels in the game.
Some versions of Prince of Persia 2 had a bug that let you beat the first ruins level by immediately exiting through the entrance gate before it shuts.