Not bad
It's a good game overall. The first attempt to play this, I also sucked and thought it was too hard. There's a bit of a learning curve with this game because the gameplay is totally unique. You have to learn to click the slingshot instead of dragging and pulling, because that just will never get you through the game. That, and the discovery of the beauty of using the space bar to pause to power up cats. With those two elements discovered, I beat the whole game the next time around.
The art is great, and I love the different cat enemies and boss. The whole game system was great with the upgrades, turrets, traps, and help from a clown, lol. Humor added a bit of character to the game as well. The beginning tutorial is priceless, and helpful.
The music was rather soothing and appropriate, and I liked the boss music as well. All the sound effects were appropriate and didn't get annoying even after playing for a while. You added some medals for the game which is good also. It gives the game replay value, and a reason to learn how to play.
Overall a great game with tons of detail and character. It's obvious you put a lot of work into this, and it's good to see author's polishing their content rather than submitting 'unfinished' or 'demo' flashes. It's not often author's go quite this far with a simple game =) Which mostly made it worth playing. Keep up the good work.