Great aesthetics! One of the best looking games in the jam. The sound pitch change is great idea.
The shotgun mechanic isn't really a part of the game though.
Great game! Nice job.
Well, the shotgun is in the game. But it's not exactly mechanically shotgun. It could have been any other weapon and nothing would change.
Shotgun (as a weapon) is usually characterized by short range of fire, significant recoil and large bullet spread. And there is nothing like it in the game.
Also in the culmination part of the game it rather resembles machine gun when a shotgun, but that's just nitpicking.