The game is fine. The game is short, movement is fluid and works with the demons.

I had a fun little moment for myself when trying to figure out what shit is by looking at the sprites and the shooting being limited to how fast I can press the mouse button made it a little exciting.

Some sound effects would be nice. for even if they are bad; I can just turn down the volume.

The demons have their own issues, Purple is stupid slow and aiming for him was a bitch but that might be just me. The red things were bullshit until I stood in a corner, shooting their spawn point. Green thing, same method as red, and lastly, yellow lightning thingy was where a bug happened and I proceed with minus lives. Had up to (-14) by the time I finished the game.

If your code states that when you hit zero, you loose - Change it to, if 0 or less, you loose.
I also died and respawned before getting minus lives so check that also - if need be.

The game is far from perfect, but there exists a lot worse on NG. You finished something, in which is a lot more then a lot of people can say about their projects.

You did good! Keep at it and improve!