Cold, cold, cold as Alaska and the Yukon put together. Thankfully, you usually won't freeze to death.
Ice Worlds may be the Green Hill Zone or The Lost Woods in the wintertime or may just be a colder climate. Ice is in great abundance for your slipping and sliding pleasure, and expect Super Drowning Skills if you fall in the water. Even if your character can normally swim, he usually finds himself turned into an ice cube if he falls into the water of an Ice World. Ice Caves are a common variation/addition.
Enemies of an Ice World usually fall into three categories: Animals found in the Arctic or other generally cold areas (penguins, seals, polar bears, etc., plus the occasional Yeti or snowman) who are trying to kill the hero for no good reason; Mooks equipped/designed for cold weather, and "ice versions" of enemies found in other areas.
Perfectly cubical blocks of ice are also surprisingly common, and can usually be moved to solve puzzles, or melted with fire-based attacks. Careful, as these blocks may have enemies frozen within them.
Slippy Slidey Ice Worlds are also a common example of a Single-Biome Planet. It's one of the more realistic ones, depending on how far the planet is from its sun.
The term "Slippy Slidey Ice World" was invented by the UK computer game magazine Amiga Power to describe what they considered to be an irritating trend of making platforms slippery just to add Fake Difficulty. Of course, as far as this trope is concerned, it also encompasses non-slippy, but snowy, worlds.
These levels have become a staple of platforming games and it's rare to find one without an ice level. As another UK gaming magazine, NGC, put it, "leaving out an ice level is like eating baby Jesus. Not a right thing to do". However, the first world or area of the game is almost never an ice world.
Expect soft, echoey, "soothing" music which may not match the tone of the game, especially if it's an RPG. Alternately, there's a good chance (especially in older games) for ice levels to have a Christmas theme, in which case expect to hear public domain carols.
The Slippy Slidey Ice World has even been given its own "holiday" in the form of Obligatory Ice Level Day. You'd think Christmas already counts, but 1) a minority of climates have snow and ice then as opposed to other times of year, and 2) Christmas is about a lot of things, just not ice levels.
Contrast Lethal Lava Land. If they're in the same level, you have just reached Hailfire Peaks.
The Antarctic level of Transformers Armada. A bare wasteland of ice, broken up by a few icebergs and ravines... along with a crashed icebreaker and plane, abandoned research facility (blow up the buildings to find Mini-cons) scanner droids, spider bots, and the first boss of the level being freaking Starscream.
Part of Brutal Legend's map is the Dry Ice Fields, it's a non slippy version of this trope.
One of the levels of Bujingai takes place on an ice mountain. You don't actually slip around, but for the first part of the level your life points are slowly drained by the demonic atmosphere and you can re-aquire them only by smashing ice cubes containing the health orbs.
Dark Souls has the Painted World of Ariamas, a hidden world inside a painting built to hide things that are dangerous to the Gods. The area you explore is a castle blanketed in snow.
Shining The Holy Ark has this while you're traveling through a mountain range. The dungeon is split into the underground section and an surface section complete with Frictionless Ice. The problem being is that the surface is covered with holes that will drop the player back into the underground section near the beginning, annoying almost everybody who played the game.
Level 4 (Arctic Caverns) of Battletoads, elements of which reappear in level 4 of Battlemaniacs and level 2 of the Arcade Game.
The Blood of the Cybermen episode of Doctor Who: The Adventure Games takes place in Geological Survey Outpost Zebra Bay, a frozen base in the Arctic Circle.
The floes and icebergs in the Arctic and Antarctic levels of Endless Ocean Blue World aren't slippery, but the water, while not instantly deadly, makes you run out of air more quickly until you apply a special insulating wax to your body.
Sector 5 - ARC from Metroid Fusion also fits the trope. An interesting example in that—like Norfair and Magmoor—the extreme temperature actually will harm Samus if she hasn't gotten the Varia Suit prior to entering the area.
The Phendrana Drifts level of Metroid Prime qualifies. This level subverts most of the traditional ice-level conventions, with the exception of heat weapons as a great ally and the very soothingTheme Tune (well, the first section of Phendrana).
Metroid Prime 3 has the planet Bryyo, which is mostly a volcano-ridden tropical jungle but has an icy section accessible through a special warp tunnel. However, the ice aspect of the area is purely cosmetic, and pretty much irrelevant to gameplay.
Sector 2 in Metroid: Other M. It's kind of like ARC in Fusion and Phendrana in one.
La-Mulana has the Graveyard of the Giants. Also subverts the musical expectation in having a thick, heavy background music to it, despite being a slippery ice level.
The Little Mermaid has the Sea of Ice as its third level, though there are few places where Ariel gets out of the water. It's more notable for the falling ice blocks that thaw into live fish.
Avalon Code has one that you have to go through twice over the course of the story. It's hard enough avoiding cliffs and pits the first time around, but the second time there are more of them, often in conjunction with speed-up floor tiles.
The cursed version of the Kujara Ranch Level in Tomba! 2 is nothing but snow and ice.
Loco Roco has Shamplin world with slippery ice. However, you'll love ice levels in that game.
The very first area of Castlevania: Dawn of Sorrow is set in a snowy village. Little in the way of snowy level gimmicks though, except for a yeti enemy that you have to coax out with curry. In later areas inside the castle, snow can be seen on the tops of rooves, indicating that the entire castle is set in a Slippy Slidey Ice World.
One could make a case for the third Harry Potter game. The "Glacius" challenge basically consists of this, except you freeze the area yourself. And yes, you really do slide around most places, but you cal also die if you fall off.
Okami has the entire northern land of Kamui. Demons are trying to make it even colder, to the point of being uninhabitable.
Okamiden has the Ice Room. It's basically the freezer for the imp chefs.
Super Mario Bros 2 also had Flurries be affected by the ice like you do, slipping and sliding as they try to run across it and ram into you. When they are not on ice, they walk slower but have greater control of their movement.
Hotel Mario brings us Larry's Chillton Hotel, which combines this with Blackout Basement — only the floor you're currently in is illuminated, and you'd never know what's going on in the other floors until you reach it.
The level "Awesome" in the Special Zone of Super Mario World; not only an outdoor ice level, but also the only outdoor ice level in the game. That aside, the trope is mostly averted in the game, though a few of the secret levels are icecaves.
Justified Trope: The Slippy Slidey Ice World is the very first level in the Amiga game Fire And Ice. Reason being, the main character defeats his enemies by freezing them and this is easier if the ambient temperature is low. Needless to say, later levels consist of deserts and lava.
One of the water bosses in any given Mega Man Zero or Mega Man ZX games will be Ice: Blizzack Stagroff, Poler Kamrous, Chilldre Inarabitta, Fenri Lunaedge, Leganchor the Gelroid, and Bifrost the Crocoroid all have stages that are partly or entirely on ice or snow.
The Calinca Ruins in Mega Man Legends 2. In fact, all of Calinca Island and the Forbidden Island can be seen as examples of this trope.
In the third game of the Valis series, there is a Nintendo Hard ice level which, at one point, requires you to accurately jump onto a platform, duck to avoid the low ceiling that will push you into a Bottomless Pit, and then use a special slide maneuver to get over yet anotherBottomless Pit.
Kirby often has this as well (as any self respecting platformer series should), with Rainbow Resort from Kirby's Adventure, Ice Berg from Dream Land 2 and 3, and Shiver Star from 64 (although only the first level was heavily ice-based).
Don't forget Cold Course and Frozen Fantasy from Canvas Curse, Frozen Hillside from Air Ride, Peppermint Palace from Amazing Mirror, Ice Island from Squeak Squad, Snow Land from Kirby's Epic Yarn, and White Wafers from Kirby's Return to Dream Land.
Freudia's stage in Rosenkreuzstilette is one of these without the standard Mega Man ice physics (and more Instant Death lasers). Sichte's stage has the physics but no ice.
Several levels of Jumper Two contain patches of ice which Ogmo can slide on (even in mid-air, after you step on ice). Sector 7 of this game takes place on a snowy Mt. Hap-Hazard, where regularly blowing wind is the most dangerous obstacle. Sector 3 of Jumper Three plays the same role (minus the wind).
Boardin Zone (no, that isn't a typo - they left out the "g") of Aero The Acro Bat 2. This level is notable because there are almost no Mooks to be seen (although there are plenty of other obstacles such as razor-sharp ice crystals), and the titular bat is on a snowboard for the whole thing. There are a few places with water, but thankfully you don't have to go under it (and not so thankfully, you die if you do).
The Northpole in Jett Rocket. In addition to frozen pools, slippery ice, and breakable ice crystals, it also has cybernetic whales! You know, just because.
Banjo Kazooie has one and a quarter of these-Freezeezy Peak is a fairly standard example (barring perhaps the evil snowmen that cross into Goddamned Bats territory due to their skills as flak batteries...), while the season-themed Click Clock Wood finishes in winter, converting The Lost Woods into a Slippy Slidey Ice World.
In Lego Star Wars, a game that plays like Star Wars set in a cartoony platform game world made out of LEGO bricks, Hoth is pretty much one of these, complete with a lot of sliding around on one's bum. Star Wars games were, at one time, a massively popular genre unto themselves- and every single one boasted a Hoth level, mostly because it constituted the only major ground battle of the films not prosecuted by teddy bears, bar Geonosis. See Best Level Ever for details. This became SO infamous that when the growing profusion of World War II shooters became tiresomely cliched, Penny Arcade's declaration that "Omaha Beach is the new Hoth" was scathing.
Ape Escape could have cared less about freezing. Spike, the main character, sprints around the Ice Age wearing a T-shirt and shorts (though water is so cold that it causes him to spring up in pain rather than swim).
There are some in the Spyro The Dragon franchise. A good portion of them have ice skating and hockey as minigames.
Spyro The Dragon 1998 has the Ice Cavern (amusingly, it is an ice-themed level in a desert- and canyon-themed hub world).
Bug! has the Burr-ubs. An icy stage, there are surprisingly few slippery areas. Made up for by the annoying snow fleas, and platforming sections over a Bottomless Pit. The boss was an abominable snowbug.
The Mario Kart series has Vanilla Lake from Super Mario Kart, Frapple Snowlands and Sherbet Land from 64, Snow Land from Super Circuit, a different version of Sherbet Land in Double Dash, DK Pass in DS, DK Summit in Wii, and Rosalina's Glacier in 7.
Supreme Commander has Luthien and Seraphim Two, Single Biome Planets covered in ice and snow - surprisingly, the latter is the homeworld of one of the three major factions. It's a Real Time Strategy game, though, so the cold doesn't do anything. The Forged Alliance expansion adds Blue Sky for another frozen world.
The Valley of Repose in Pikmin 2, though besides the snow the only other wintry elements are a few Christmas-themed treasures in the Frontier Cavern.
Ancient Domains Of Mystery has one near the end of the game, and it's too slippery to use spiked boots. Throw the tons of Clingy MacGuffins to get past. The gods will also reward you if you use a Potion of Uselessness for this purpose.
Joke's End in Mario & Luigi: Superstar Saga. Interestingly, its snowy climate isn't caused by high altitude, or proximity to the poles, or wintertime, or — for that matter — any other environmental effect. No, Joke's End is cold because that's where bad jokes go to die, and they bring with them their audience's frigid reaction.
In Final Fantasy XI, a zone named Uleguerand Range features a battlefield with pricey and valuable rewards. The cost of entry? Sliding down an ice wall and landing in a very specific spot, amidst tons of sight, sound, and magic aggro from monsters. And God help you if a snowstorm starts.
Pokemon Diamond And Pearl have probably the most annoying route of all 5 generations: Route 217, where not only can you not bike or run in the snow (even when you get to Snowpoint City), but your walking speed is reduced to almost a Shuckle's pace! Even worse, there's a blizzard going on, which makes it difficult to see and Hail during battle. Don't forget, every few steps you'll sink up to your eyeballs in a snowdrift, and have to thrash around on the control pad to get back out and resume your sluggish pace.
Pokémon Gold and Silver have the Ice Cave, which is pretty annoying your first time through—you have a few ice puzzles, boulder puzzles (not unlike the ones on Red, Blue, and Yellow's Seafoam Islands), and Goddamned Golbat are fairly common in the dungeon.
Etrian Odyssey 2: Heroes of Lagaard, true to its season-themed strata, boasts this for its winter floors. The highest floor in the strata adds to it by making the ice too thin to cross except at night, when the temperature drops. You are also given the chance to take a nice rest on one of the floors. Bad idea. The very first paragraph of this trope description should suggest why.
The Lost Age has a dungeon in an antarctic region that's full of slippery ice puzzles. They could be quite a pain in the ass, seeing as how you had to solve some just for 100% completion. There was also Imil, the whole southern continent of Tundaria, and especially Prox, so far north it wasn't even on the map. Now that's cold.
Slippery ice puzzles return in Dark Dawn with the Snowdrift Shrine.
The World Ends With You: While "Shibuya ain't cold enough for ice," there is an ice level, not in the main game, but as one of the boards in Tin Pin Slammer. In Another Day, after you go to Molco, head to the Udagawa Back Streets and challenge Mr. Kitaniji to Tin Pin. (He won't accept your challenge before then.) The board is icy, with no obstacles, making it much easier for you to send your own pin flying off the board by your own stupid mistakes. The ice does affect the other pins, however.
In Baten Kaitos, this trope is surprisingly absent. Even though there is an ice land, and you do tunnel through the snow, you don't slide on the ice. Maybe Xelha just got really good at walking on it.
Eternal Sonata has a slight version in the Sharp Mountains. No Elemental Rock-Paper-Scissors regarding the cold aspect, but there are certain paths that are sloped. You can get to the top if you keep going, but if you stop, you slide toward the bottom.
Dragon Quest V: Faerie Lea, although the ice in the Winter Palace isn't as slippery enough to get you to actually hit the wall, since you stop short when you move a certain number of spaces, it's still slippery.
And a few dungeons in 'Dragon Quest VI. The first one is short, has no enemies, and is just a single room with a slippery ice floor. The second one has slippery ice, along with cracked ice patches that drop you one floor below if you step on them more than once.
Ys II: The Ice Ridge of Noltia. Also, the Eldam Mountains in III and Oath, and the Ice Mountain in both versions of IV.
Mount Sabre from Crystalis is the game's typical "ice dungeon", complete with ice slides. It's possible to jump up these slopes if your character has the Rabbit Boots equipped and isn't using magic. In fact, it's required that you do this in order to reach an important Upgrade Artifact for your first sword.
In the Winterhorn Ridge level from Odin Sphere, you actually will freeze to death without a warming potion.
Mass Effect features Noveria, where the ice is both real and figurative, as you have to deal with a very cold reception from the corporations controlling the planet. There's also a few uncharted ice world that can be visited, though usually the only hazards are the cold temperature itself and reduced visibility, or the pirates, but you find those everywhere.
Ultima Underworld II features the Ice Caverns, which is Exactly What It Says on the Tin. Mercifully, most of the large slippery sections can be avoided entirely without missing anything worthwhile, although there's one which you do end up having to traverse.
A few puzzles in Tales Of Symphonia take place in a slippery, icy cavern. What's odd is that the low-gravity puzzles work the same way...
Tales Of Phantasia has the Cave of Fenrir located under the town of Friezkil, where Vorpal sword can be found. Alas, ice isn't slippy, but enemies do have fire weakness.
Tales Of Destiny (Playstation version) played this trope to a logical extreme in one level. You had to buy the fur cape accessory to travel in order to travel across a bitter cold pathway that will drop your HP horrendously fast without the aforementioned fur capes.
One of the most popular missions, "Arrest Frostfire" features an ice-covered room that includes ice-slides and a ice half-pipe. Seldom does a team of player characters enter this room without someone deciding to take a couple of minutes to play on the ice.
During the Winter Event of City of Heroes, the Ski Chalet appears in Pocket D, an snow-covered mountain floating in a void with a wooden shack on top and ski slopes, complete with Badges for beating the best ski times. A unique instanced map only found in this event turns Croatoa snowy.
On RuneScape, the 2008 Christmas event had patches of ice that you could only slide on until you bumped into a rock. So irritating. And again in 2010, although that time the player was a seal trying to avoid holes in the ice. Outside of Christmas events there's the frozen floors of the Dungeoneering skill, which are as advertised, including a room where the player has to slide around trying to activate four pressure pads to open a door, and a boss that is floating over an icy floor that players can only slide on. There are also two icy plateaux on the surface which continually drain a player's stats and deal damage as they remain in there.
The various areas of the Shiverpeak Mountains in Guild Wars combine this with Death Mountain. Of course, even the lady Elementalists, whose preferred attire is a bra, miniskirt, and a lot of lace, have no trouble with the cold. One mission does make note of the weather in such an environment, however-the mission is set in the midst of a night-time blizzard, and the party is tasked with lighting a series of signal fires for the NPC's following behind them.
Achaea's weather system occasionally produces blizzards, which leave players stumbling around blindly until the snow eases off. However, the snow seems to melt instantly on hitting the ground, and so does not actually create an Ice World afterwards.
The Brrrrrgh from Toontown Online. Luckily, snow and ice don't affect gameplay unless you count fishing.
Star Fox Adventures has two cold areas: SnowHorn Wastes and part of DarkIce Mines. There's not a lot of slipperiness in the former (although the Krazoa Shrine accessible from there does have a slippery floor), but they do have places where ice blocks your way, and the water eats away at your health as long as you stay in it.
The ice stages in Gradius II, III Arcade, and Gaiden.