Wow I liked this game a lot! The movement took some getting used to, but I always enjoy a 2d platformer.
The AI was quite good! I even briefly wondered if it was human players since they played so well. I thought this is a great use of the "health is counting down on a timer" mechanic - fighting with your friends like two monkeys in a phonebooth lends itself really well to fighting for a limited resource.
I liked the coins and the enemies, but they didn't respawn after the first round! It would have kept the gameplay fresh. I assume that's a bug. More NPC enemy variety would have made it more fun. I unfortunately didn't get a chance to play test with another human - also not sure how well it would work on my keyboard since multi keyboard use is limited by the key rollover which is usually quite low. But I love the concept and could see this being a fun couch game to play with a controller with friends.