Yays
I love all of Mike's work and this is no exception! After a while I finally got all of the pawprints...w00t.
Here's a hint to those who have trouble beating the game with 25 lives: world 1 levels 3 and 4, world 2 level 2, world 3 level 3, and world 5 level 2 are the only ones you should die on (and only lose 1 life when you do). The rest of the levels can be beaten without dying.