I don't think you scaled the damage overlay properly for my 1440p screen

First off there is a delay with the cursor movement. I don't know what you are doing in your code to have this much of a delay but please remove it.

second there is a weird mirroring with the cursor so the lighter one is the real one and the stronger one is just there for no fucking reason. The real cursor is the bigger one but it is not where you are shooting and it is not fun. Why the fuck am I even trying the basic shooting is so fucking garbage. It's fucking basic as shit. You purposefully added more than what you needed to to make the game worse. You turned one simple and elegant line of code into 5 lines of retardedness. You are just making something simple complicated which is never good. Just remove the second cursor since that does fucking nothing and allow bullets to shoot to the main cursor.

The character is too slow and has no real freedom in movement.

Music sucks ass and feels empty. but since you are using www.openmusic.org instead of making shitty ones it makes scene. Maybe make the music louder. i don't blame you for using openmusic but you can get better music that is royalty free on youtube or bandcamp which will add more flavor and the game will feel better overall for the player. You want the player to have fun and decent music will help. Drop the chiptune style since it sucks major ass and you can get better music with less effort if you end up making music yourself.

There is also the fucking voice which is grating. Put the voice down for that a bit and has more sound effects and music play more for more immersion. It's fine but your music and sound effects should have more of an impact. The voice is a sound effect and you shouldn't treat it like a main theme. 

The art looks pretty good.

I believe this game will get good one day if you change some things for the better.

4/10 game right now but since it is a demo I rate it 6/10.