Not that bad as some people said. I know when you say- "fighting game" - people expect freaking street fighters quality fighting game with crasy ass effects.
Look, this is a nice little game and you made basic game engine that works alright. And you did try making characters look close to the ones in cartoon. I know it's not easy. I like how powerups give various weapons to use. I wish they would be more variety and different effect.
Also- ingame Peter looks okay, but Chicken looks like was drawn in more rushed way. If you ever get back to making new game - I would suggest make characters have longer hitpoints, so we can have longer battle.
Make more stages, maybe scrollable a bit to left and right. Various weapons have different range and attack style, speed. Add more characters, if it's not too much trouble. If not, then finetune chicken and Peter.
Make AI just for the heck of it. Make various difficulties if you know how.
Don't listen to those who just slam on your effort. They didn't even give any suggestion for you.
P.S. - make various sounds when characters get hit or hurl a hit.
is terrible i suggest a little more umph
this game isssss assss
this game is ass
vary good but confusioning?
i didnt no it waz all 2 playerz