MouseCraft is a cross between Tetris and the Lemmings, but with mice involved. It is a puzzle where players help mice in their quest for cheese by stacking up Tetrominos (tetris blocks).
There's a Crazy Cat Scientist that you have to watch out for and a lot of cheese. There's a video trailer here and these are some features:
MouseCraft is cross-platform, so Windows, Mac, Linux, consoles - you name it.