The complete Cat Physics walkthrough from level 1 to 50. (Some link lovin' goodness to the creator of the vid below. ^_^)
Some commented on this video that the level 48, which is the Fragile Bridge level, won't work so here's the guide to that level.
Also, level 35 is another difficult one to finish so here's the walkthrough for that level.
I hope this Cat Physics iphone game walkthroughs help you beat the game and please do let us know how long it took you to finish the game.