Wow, well certainly the scale on this game was impressive! The multiple planets with the different mechanics was cool, and the madness had some fun effects.
I also liked the little details like the optional weapon, using a photo of a cat to restore sanity, the moving star field outside the window, etc.
I found it interesting how it had the kinda cutesy pixel graphics at first, and then got creepier and more lovecraftian as it progressed. It got real eerie with some areas!
I do however have some issues with the game.
The most obvious to me, but is also the most subjective, is the controls. Having Q and E be strafe and A and D be turn messed me up the entire game. I know for a number of dungeon crawler fans that can be eprfectly fine, but as someone who has WASD basically hardwired into their brain I never fully adjusted to it.
The FOV for the camera I found a bit too claustrophobic. I don't think it needs to have half the tile underneath the player visible like some dungeon crawlers, but I think being able to see where the floor starts would be better for orientation. It made it hard to tell which square I was on sometimes. And combined with the fact that some interactions could be done from more than one tile away (while convenient) made it more confusing.
A recommendation I have for the game to avoid confusion though would be to have the player automatically return to ship after beating the boss enemy, or add a popup recommending the "return to ship" button. I wondered around for about 30 seconds thinking it wasn't dead yet or there was going to be a second phase until I remembered the return to ship button. So maybe add that for the slow people like me lol.
Also like other comments have mentioned, the combat is a bit odd. The rotating towards the enemy you're attacking can be disorienting, especially in the final boss fight I found. And the fact that enemies don't always face the player can sometimes make them hard to aim at.
Overall though I was very impressed with the game, you managed to stuff a LOT into it!
Great work!