This was a BLAST! Definitely reminds me of being a little kid in the school computer lab and finding fun flash games when the teacher wasn't looking if that makes sense at all lol.
Definitely got myself engrossed in the game loop and felt myself wanting to keep coming back to get a higher score. The visuals also feel really well done.
I do really wish there was some audio here to really sell that player feedback, and if I had 1 gameplay critique, the ADS feels like it covers too much of the view, and the bullet positioning vs the center of the screen felt a bit strange (was never 100% sure if my shots were landing), but that didn't stop me from having a killer time with this!
Left a good rating for you :)