The concept is a great idea, however not being able to increase the range at all makes it really tough when two zombies can kill you extremely quickly if they are quick or ranged and just sit by the gate, waiting. Very promising game though.
Perhaps if you made the jump push-sensitive so we don't always have max height? Also possibly having upgrades for faster running speed or more weapons?
This is a great game, but it needs a button that lets you drop a new cat. I had sushi cat get stuck with only one pice of sushi left and had to restart the whole level.
In the sequel...