Decent... but not astounding.
I'll leave it to you to make it better... but the only problem with it right now is that it has no point. I killed a crap load of Zombies, and for what? To walk off into the sunset. It would have been nice to see some sort of teaser for the actual game... some weird "DUN DUN DUUUUUN!!!" scene. That would have brought the fun factor in this game up higher. The controls are a little slow, but decent... and the graphics are nice. I do like the fact that there's characters from each of Newgrounds popular shows... So I hope it keeps up with it. Keep with it, and I hope to see the full game some time soon. :)