It only plays on 720p, 1080i, and 1080p which are all HD formats. Your TV is probably something like 576i because you're in the PAL region. Some PS3 and Xbox games will play 480p and 576i, but this particular one does not. An upgrade to an HDTV is necessary for correct display.

I have actually had technical problems before because I was playing Assassin's Creed on the wrong format. The colors were all ghetto and green. Then I just switched the format display for my XBOX 360 and it worked fine.