It's neat but it's not fun. The Jam version at least.
- Cool base idea, very bold choices for a survival game.
- The base controls are pretty good.
But maybe the learning floor is too high to be enjoyable, especially for a 15 minutes-to-clear game. Like, the game asks *a lot* from the player to try getting as far as wave 4.
- There's very little room for errors to be made - there's so few margin that the experience doesn't go smoothly. The game is so unforgiving that the fun is sucked out of it.
As for why it feels that way, my guess is: either the controls and mechanics make the player too helpless for the challenge OR the enemy waves are not suited enough for the available controls and mechanics.
I guess you could try adding checkpoints instead, which wouldn't discourage the player to continue after a Round 3 game over - in that case leaving the gameplay as it is should be actually okay.
Here's gameplay where I managed to clear the game (Jam version). Hopefully it gives my fellows a way to see more of the game and rate it accordingly.