Hey, thanks for adding a Mac download. As I have no friends so I checked this out solo, Definately some potential here for a decent sofa local party game. Here are some suggestions if you decide to keep developing it.

Improve the player controls. A jump attack would be the first thing, then maybe a projectile that you have to pick up (spawn it in randomly). I get that it's probablt supposed to be a fast paced game with 1-hit wins but if you add maybe a couple of hit points to prolong each round that would be good. These could be represented by each monkey holding 3 bananas, when you get hit you drop one (which could also then turn into a trap causing any monkey that steps on it to slip and lose 1 banana. (just thinking out loud). Make the sprites smaller and give the player more room to run around and away from the other player/gain vantage positions etc. You may need to increase the level time slightly for this. I think a good 30 seconds per level is probably fine. Also if players are competing, add a score system (for bragging rights).

If I'm missing the scope of what you're were intending to develop then disgregard this, these are just a couple of ideas that I thought of when playing.

Nice game! :)

the 2 player Wario Ware style game, where you sometimes need to fight and sometimes collaborate was really fun :)

I also liked the banana background.

Wow this is a weird game. I have the following feedback:

• Pack the .pck file with the .exe in a zip or better yet, when exporting from Godot select the "Embed .PCK" option.
• Do an HTML5 export. That way more people can play your game.
• The level with the platform in the middle is annoying. I can't figure out how to jump over it. It always happens as if magic.
• Add life to the players. I didn't like that one-hit to win thing. Also, it boils down to who hits the button faster, which is not cool.
• Maybe add a life-bar and a knock-back when a player is hit. This way you can add spikes to the level and players might try to push each-other. Maybe some weapons throughout the level will make the game more interesting.
• The graphics are okay-ish. A bit hard on the eyes though but not too bad. 
• Add a victory animation, player lose animation or something. The level abruptly ends with an ugly message in the middle of the screen. I know this is because of the time limitation of the Jam but it didn't feel very pleasant to look at. My game also ends abruptly so I added an Ester egg so that it makes sense for it to end that way.
• I had no idea what to do each game. I just mashed the space. Sometimes I won, sometimes I lost. Seems like there are only two minigames: Hit punch at the same time and Hit punch faster. Some more variety would be nice. Think Mario Party. I played alone as I didn't have anyone to play with.

This game definitely requires some polish. 

Couldn't run. Seems like the ".pck" file is missing

I couldn't download as I use a Mac :(

It looks fun, is it only 2 player?