I did enjoy this little game. I played 6 matches back to back and can conclude that, for me at least, the biggest problem is just how easy it is. Against the CPU at least. I can see this critique melting away with the virtue of another player.
Even solo, it's a joy to watch the sprite jump up and down in time to the players frantic taps.
The only time where I was in any danger was my first game, for some reason my keyboard didn't react at first. I played the rest of my games to try and determine what the best strategy to use against the computer opponent might be, I think it's ultimately a tie between alternating jump height and just spamming both buttons randomly. Though, there is some role for rudimentary timing to play here.
The enemy also seems to jump a lot more the lower his health grows.
The games design just does it for me, I'm a sucker for a retro-esque jam game done well, this game certainly ticks a lot of stylistic boxes for me!
If you ever polish the game, might I suggest more interaction? Just because the player is limited to two buttons doesn't mean the objects the player throws can't impact one another for instance, unless I've completely misunderstood the theme...
6.5/10
Hope any of this is helpful :)