This is definitely an original idea, well done. The graphics are simple. but the color contrasts work and the shapes are all clearly distinct.
The recharge speed on the shotgun felt a little too slow, considering that the player also needs it to maneuver. If you're concerned about making the shotgun overpowered, a compromise might be to have a lower cooldown, but less damage.
Protecting those friendly bodies was pretty difficult, but I did manage to beat the game. That was pretty satisfying!
I didn't get any audio when I played this game. If you didn't implement any audio, consider including it for immersion, even if you don't have that much time to get it perfect. (Or, you can collaborate with a sound designer, of course...)