The game is good! If played as intended, is a good reaction challenge. If not played as intended, you can easily break the game. Ronnie can use his speed and special to reach the other side of the screen and staying on there, you can no longer get harmed. Also, even the turtle is bugged as you can see. When you use the special, you can not jump, and this can make you lose. Also, for certain hits, you can jump off the screen and see this: 
The game is good, just be careful of bounds and rebalance the characters, check out the death animations and avoiding to get on the bottom of the floor and so on. The chicken can fly, but not always is useful, you should put iframes when you do a special in my opinion.