"TMNT" PS2 Game

I've recently picked this game up in a Gamestop. I wasn't going to buy it at first since I wasn't a huge, huge fan of TMNT the movie; but it's not a bad game. But I'm having really difficulty when you have to do "bird flips" up walls. Does anyone else have this issue? Or am I just retarded when it comes this aspect of the game? Can anyone give me tips how to do this without getting frustrated and spending 15+ minutes on attempting it in one spot?