Timeshift: worth owning?

Okay, I am 16 years old, so naturally I still get gifts from my parents. I just found out I got "Timeshift" for the 360. I've heard some good and bad things... in a nutshell, that it's fun, but not great. There is no receipt, though I am reasonable sure that I can still take it back and trade it in, correct? In that case, since Timeshift was a gift (I also got motortstorm from a grandparent, though plan to take it back because I already have it) should I just keep it, since it was free, or try to trade it in? I have all the major games this holiday, except for unreal tournament (probably the pc version), so the games I would trade timeshift in would be: Eternal Sonata (heard great things), Kane and Lynch (probably another rental, like I was planning to do with Timeshift), Eye of judgement... I'm sure there are others.

Anyone who doesn't feel like reading that semi-wall of text... basically, should I return Timeshift for something else, while renting Timeshift, or just accept it, since it was free. Help would be appreciated.

Yeah, i'll probably just gamefly kane and lynch, and try not to let the Jeff thing get in the way... I'm still not convinced that was the cause, however.

So yeah, the only other games I want this year are Eternal Sonata and Unreal. I'll probably keep timeshift, it looks fun.