This concept is really amazing. A long time ago I tryied to do it, but it became very confused. Maybe only 2 "worlds" should be enough to be better. But in overall, it's very good concept.
Sometimes I died to myself just because I changed the world. I think the "colision area" of the cat was hitting some scenario colisions causing me to die. (idn)
However, this is a great concept game and a pretty insane artwork (level and sprites). A good work,dude!