Sims 2 with Spaces

[iFanaddic]

Is there a way to exit a fullscreen game without quitting it? Im playing the sims 2 and I would like to be able to go back to my desktop without actually quitting the game and go back to the game when I feel like it. Maybe that would be possible to do this with spaces or I don't know? Doesn't the game have to run in full screen mode? (If any of you remember the apple demonstation that showed us the fonctionalities of spaces the guys was playing a Golf game while he was doing something else in the other spaces. thats something I would love to do with the sims 2.. is it possible?)

And what should I do when my game freezes? I'm stuck in full screen mode and I don't know what to do to do to quit the game. (in windows I would got ctrl+alt+delete but im on mac now and I don't know what to do..

Thanks for the help.