Good job. Considering it is your first real game, respect.
It featured all of the essentials needed. A good gameplay loop, great sound effects, and a good UI design.
A few criticisms would be:
- The UI doesn't scale very well.
- The enemies spawn near the player. You can see them pop up in your viewport, which looks in my opinion a bit strange.
For what it should be it's amazing.
Keep going.