Transformice

In this game, you control a mouse whose goal is to try and return with the cheese faster than all of the other mice. You are assisted by a (point based) Shaman, who has the ability to summon various physics-based objects to help the mice get the cheese and get back safely. Mix this with numerous fun glitches, and shaman trolls and you get pure and utter chaos.

With 110 official maps and an uncountable number of user-designed levels, as many as 100 psychotic mice bent on getting the cheese first, and Shamans who have no idea what they are doing the game quickly turns into a hilarious and unpredictable mice frenzy.

(~http://transformicewiki.com)