Ice cave This map was later added during the Christmas event 2011.
Ice cave is a really creepy close-quarters map. The best choices are to take a shotgun and start the massacre, and avoiding the acid vomit from the Bloat because he is fairly effective on this map. Also Fleshpounds are hard to take on your own because he doesn’t need to sprint that far to get to you.
There are some tactics for lower difficulties such as welding yourself inside one of torture rooms that are pre-welded each round which could make an easy camping spot. For higher difficulties you should better go on a higher spot like Santa’s throne and take about two medics and four support specialists so you can blast some heads to shred, or camp inside the tunnels but the holes in the wall make an irritating spawnpoint for the specimens.