This is pretty good. It definitely feels like a pretty full-featured metroidvania platformer.
The only things I could critique would be 1. the amount of space the camera takes up, making it so I don't see as many details in anything that you drew and also 2. I don't like the keyboard layout. I wanted to press W to jump and Enter to shoot. E is not well placed for that because my index finger already has to be on D so I don't have any finger positioned well for E. So I reach across the keyboard with my opposite hand. Space for jump only feels right when I'm using the arrow keys with my right hand but I'm already used to using W so why not just use W for jumping?
EDIT:
And I forgot to comment, I thought it was cool that the dangling chains are pushed by those sliding walls.