The presentation was very nice however the gameplay could use some rethinking.
Giving the player a single bullet makes perfect sense for the theme, but it’s not very good for gameplay. If you miss a shot you’re basically just sitting around waiting for more ammo.
The most important part of a top down shooter is the shooting, and if you’re not able to shoot it gets boring pretty quick.
There’s a lot you could do to fix this but I think a cool idea would be to have enemies get stronger/faster/bigger every time you miss a shot. If you hit an enemy in one shot it dies instantly but if you miss, all currently spawned enemies get stronger requiring 2 shots. You can shoot freely but inaccuracy will lead to a more difficult time surviving and scoring points.
That probably has a bunch of flaws that I haven’t thought about but it might be an interesting idea to explore