This was my favorite game in a lot of areas this demo day. Your level design is good! You should be proud of what you've put together here.
I agree with whoever mentioned the game has ESA vibes: it very much does. And that is a great thing.
I don't know if anyone else mentioned this but you mixing the retro sfx with the more grounded foley like the cave ambience works surprisingly well, and grants a lot of life to the station that wouldn't otherwise be there, audio will be your friend on this project for making the world feel alive since you're sticking to monochrome graphics.
I didn't find it immediately clear that the big gateway things are save points. That might just be me being stupid, but a lil text pop up when you interact with one would go a long way to making that more obvious for oblivious folks like me :)
Your first boss is good! I would maybe force him to use his moves in alternation, because on my first attempt due to some wild rng I didn't even know he had more than one move.
Overall the whole thing was a joy to play, and I love the main weapon. Your gravity gun is a lot of fun too. Hitting a lot of very base satisfaction receptors with this.