This was really awesome! The shooting mechanics feel really good, the style is well executed and consistent, and the gameplay loop plays into the theme quite beautifully as well. It's really quite impressive what you've done as a single developer.
I do think the base ground texture makes the player blend in a bit too much. The white border helps, but decreasing the contrast a bit could help as well. The only other minor detail I would mention would be that it could be good to make the timer more prominent at the bottom of the screen. I went in the first time having accidentally missed the last couple lines of the queen's dialogue and I completely missed the timer lol. That's on me for not finishing out the dialogue, but it could still be good to add some more cues to tell the player to get back when the time is running out since resetting the game can be a bit punishing.
Either way, fantastic work!