Thank you for playing my game. I had to make this game about 3-4 days.
At first, I designed my game to be rouge-like, but due to time I had to cut out the map generation and manually made the maps.
When I tested the game I didn't have the issue where you couldn't shoot. I have to investigate it further. Maybe as you said, it can be a frame rate issue.
Again, thank you for playing my game and giving valuable feedback.