Here is the full list of all 10 Croc's World Construction Kit 2 achievements worth 1,000 gamerscore.
You´ve played online levels for at least 45 mins!
You´ve added more than 100 enemies to a level!
You´ve created more than 20 levels!
You´ve rated 20 levels!
You´ve rated 5 levels!
You´ve created more than 3 levels!
You´ve added more than 20 enemies to a level!
You´ve rated a level!
You´ve played an onlinelevel!
You´ve created a level!