I love low-res retro games so visually your game was spot on for me :D
Artwise, the ambience, textures, basically everything thatg can be considered art is top notch, even had some space-horror feel.
The movement is smooth and the controls are simple, I also liked the puzzles. Altough it wasn't clear for me what I've picked up at the beginning but I guess it was a breathing device,
It wasn't 100% clear at first what are the floppy disks I'm picking up, I thought they are checkpoints, then seeing they are colored it got clear pretty quickly that they are the keys for the doors - with a matching color.
I can get lost in maze-like maps really easily so sometimes I was a bit "scared" I won't find what I need but I managed to play it trough until the end - a small minimap wouldn't have hurt but me myself haven't implemented one for my game, so I accept it :D
Overally it's one of the best submissions taking my personal taste, so good job - even better thinking this is your first Godot game :D