The UI is simple and it does it's job, but it could use some work. The music is great though, really atmospheric.
The pause button doesnt work, also the Exit button after clicking pause ingame doesn't work.
When I started playing I tried to shoot, thinking a projectile would come out, but it's basically click on the enemy. I do think the game would have been more fun if you shot a projectile instead.
The sprites could use some walking animations.
The world itself is pretty good looking, so good job on that.
The barrier looks like a skewed 2.5d? picture.
The gun should rotate at a point on the handle, I think it's easy to fix. but maybe it was overlooked in priority of other things.
I think you should try to stick to one style, as I am seeing Pixel art (on the main character), non pixel art on the Level itself, and what looks like a 2.5d skewed picture on the barrier. Also some of the text is Pixel art and some is normal. If you made everything consistent with one style, it would be way more uniform and pleasing to the eye.
I think the time limit affected you a lot here, but it is still a working game, the gold covers the limitation as one resource.
Great work delivering a working game! And please keep making more games, see you in other jams!