This game makes no sense.

[GAGA Extrem]

Why is this game so demanding on my graphic card? The graphics aren't fancy at all. This makes no sense.

(1) The game is quite demanding to GPUs, because a lot of calculations (and iirc not only GFX related stuff) is done there to make room on the CPU. Remember the game has to calculate actions and behaviour for hundreds of characers.
(2) There seem to be issues with V-Sync. Check the tech support for detailed solutions.