How to minimize windows like on Windows?

view full story

http://askubuntu.com – I looked it up on google but I didn't find anything helpful. Anyway, I was playing Crysis 2 (with PlayOnLinux) and the game crashed, but I could't kill the process, I tried CTRL+ALT+T but nothing but the game appeared on the screen, I had to CTRL+ALT+DEL and finish the session, also losing all my work. On Windows there's the Windows Key (which opens the Unity Panel), but I can't do anything. And there's CTRL+ALT+DEL which opens all the processes (on Windows) but the terminal doesn't show up on me (CTRL+ALT+T), I can't kill any process. Any help? (HowTos)