Sonic Advance/Zone 4

You are now arriving at Ice Mountain, a snowy wonderland where some of Eggman's coldest badniks roam. If you happen to land yourself in the icy water, find the bubbles before you run out of air.

Act 1
Head to the right, until you reach the first tunnel. After this point, you will need to go through an underwater section. There are three entrances, and to minimize the time spent underwater, you will want to try to go as far right as possible. However, if you enter a little early, you can look for air bubbles down and left of the four rotating platforms. You should eventually come across a pillar blocking further access to the right, which requires a rather high jump. If you can't swim over it (like Tails can), head down, and use the bumper to throw you above that pillar. Reach the checkpoint, and get the air bubble on the platform to the right. Jump up, and use the spring to exit the water. You will eventually need to return to the water. When you get there, jump in on the right-hand side of the spinning platform, and use the springs to jump across the bottomless gap (and another spring to exit the zone.)

For the Chaos Emerald: you should see a split route after the first Point Marker. Take the higher route and follow the path (using the moving platform to get across the gap; you should see a penguin badnik along the way). Eventually, you'll come across more moving platforms. Hop from one to the other to the platform on the other side, and in front of you will be a slope. Spin Dash up the hill to reach the rotating platforms above (use Amy's Hammer Jump) and jump to the platform to the left. Take the spring to another (downward) slope, and let the spring on the end send you to a new area. Get up the hill, use the spring to bounce up to the platform above, then do a big jump to the left. You should bump into a wall, and fall down to the Special Spring.

Act 2
Like the previous act, there is water in this level. However, you can proceed through most of the level without even touching it, as long as you remain as high as possible. Follow the high route (bounce on the springs floating on small platforms), then right. Take the zipline down, then smash the rock in your way and use the spring. You'll end up on a platform with an Item Box and a spring. Take the spring to end up on top of a loop, then drop down and continue right. Use the spring ahead to reach a platform with another Item Box, and hop onto the moving platform when it reaches you, using it to get to the platform above it and eventually land. Use the spring here to be sent to another landmass, then drop down to the left to end up right on top of the Special Spring.

This boss fight takes place underwater. Dr. Eggman will walk across the cavern ceiling, and smash to cause icicles to fall. To damage the boss (in addition to getting air), you need to jump on the icicles, then jump at Dr. Eggman to damage him. As Tails, you can swim to the surface to get free air. Amy Rose doesn't need to use the icicle platforms, and can attack directly.