Positive:
-New stuff
-Chain puzzles
-Humor was great, not a moment I didn't smile when the A.I"s said something
-co-op was fuckin brilliant
Negative:
-Singleplayer was alot easier than co-op
-To much use of the gels insted of mixing it up more (mix of gravity beam, gels, jump thingies, etc was perfect in co-op)
-A lil short (still more than the avarege game nowadays)
Overall 8.5/10...I feel like co-op just needs to get alot more content (or balance singleplayer more) but the game was really worth the money. I'm really glad I have some friends who enjoy playing co-op with me...even more fun to rewatch our recorded gameplay just see how stupid we can be at some points. :P