Extremely cool and unique concept and a first-person Metroidvania was something I did not expect. The progression is straightforward, and the level design points you into the right direction.
Visuals are cool, too. The PS1 graphics work.
One thing that would be a nice-to-have would be more juice during shooting. It isn't really clear when and how much damage you're doing to the enemies, but other than that it's a great project.
Well done!