I like the artwork and the UI design that was put into this game. I do think having to click the exact spot in order to hit the enemies more precise than needed for this type of game. Most of these do a raytrace or projectile to see if you hit anything going in the direction of the cursor. Your gun taking away your time if you used it too much at once adds a nice tension and if you had more elements that forced you make choices between firing the gun to complete some non-critical objective or staying alive, it would add some interesting dynamics to the game, similar to other roguelikes where you can choose a harder battle for better rewards at the risk of dying or choosing an easier route. The horde portions sort of hit on that, but I think you can push that idea further.
Minor nitpicks I had was the UI color choice for the dialogue text lacks enough contrast and is slightly hard to read and the number of hourglasses you have is not really visible in brighter areas as it blends in. I really enjoyed this game.