The Frozen Tundra is the first level of The Wilderness.
Walkthrough[]
First, you stumble across five Prize Bubbles. These contain Pony Tail Hair Wig, Long Grey Coat, Fur Hat, PVC Raincoat and PVC Trousers costume pieces. Jump and grab the Prize Bubble of the Bear before moving on; he tells you his family has been kidnapped by the evil Collector. Choose the top sled up ahead. A prize bubble containing the Rocket Dog with Sled Object is up ahead. You can only get it if you are on the top sled, and you have to jump up to reach it.
Follow the slippery path downwards, and get out of the sled after crashing into a soft wall of snow. One of the Collector's machines is behind you. This introduces you to what to expect later; lots of moving, electrical parts. Locate the gear-shaped Sticker Switch further ahead and make a note of it (it may be a little hard to notice at first, for it is in shadow. It's by the Checkpoint). Once you have the Black Gear Sticker, which you collect in this level, put it on the gear-like object. Two prize bubbles will drop, containing the Pink Splat and Tree costumes (they are both Materials/Skins).
A sackboy playing the Frozen Tundra
Carry on, and you'll meet sets on ledges on three tiers; higher in the background and lower in the foreground. Each row has its own Prize Bubbles. The upper ledges are much harder than the lower ones. On the back- and middle-ground ledge sets, large icicles destroy the ledge when you walk on it. The icicles drop faster on the higher ledges and the ground is slippery. There's no obstruction on the lower ledges, so it's your safe bet to get across. At the end of the higher set are some rare Prize Bubbles, while if you take the middle path you can knock a block down to get at the goodies later on.
Regardless of what route you took, you should be at a Checkpoint near some red girder-like structures, and down below are some Prizes. If you knocked the block down from the middle-ground set of ledges before, you should be able to get down. There're some more enemies and falling icicles and a slope in the background. You can use a fallen icicle to get up here. Jump off the slope and head right. A sequence of larger icicles drop down near a dead-end here. You can use them as a set of ledges to jump up left, and then more fall down so you can jump higher - to the right above the wall that was blocking you.
Next is another girder-like structure, and a little army Jeep will race away from you, blasting holes in the bridge. Neither him nor the blast (and nearly inevitable fall) can kill you. Also, if you drop, go left for a hidden Prize. Now, regardless of whether you fell or not you should be on the other side of the girder-bridge.
A sackboy playing The Frozen Tundra
Drop down after the bridge to find a set of Race Gates. Going left, you have to slide down some icy ramps to reach the goal. There are lots of little jumps, but don't press 
, else you'll jump too far and miss the Score Bubbles and Prize Bubbles. At some stages you'll have to quickly switch layers to stop yourself from coming to a standstill. If you're fast, it's actually possible to get a x20 Multiplier and the Trophy that goes with it. When you reach the end of the slippy slope, you come to some boxes with army men on top; you can give them a push to knock down the prizes. You'll now meet The General, who'll give you access to The Bunker. Run ahead to the right and destroy the enemies here. There's also a 4-player challenge area. Run back and grab The General, and pull him with you back to the right now that the robots are clear. His Magnetic Key will open the door and you'll be able to clear the level.
Multiplayer Challenge[]
Just past The General, near the level's end, is a four-player challenge. You need four people to stand on a red switch each to work the elevator. It will take you up to the next part. You'll see a pattern of 4 stickers on the wall, and to the right are four red dials with a set of pictures around them. The players have to grab and point the dials to the corresponding picture in the sequence; the first dial must match the first sticker and so on. When all are matched, the path to the right will open. There is a springy platform in this room, with a switch below it. All four players have to jump in time to bounce the platform until it eventually dips low enough to hit the switch. When hit, the Prizes will rain from the ceiling - a Devil costume and some stickers. To exit, head left until you find an icy chute. You'll need quick reflexes at the end, for at the end of the chute is The General's Prize Bubble, and you have to have sufficient speed and jump height to get it. That said, one of the four people will most likely burst it.