The ambience is great! As others have said, it was a little disorienting to navigate; I feel like the very low resolution contributed to that a bit, since it impacts visibility. Just the darkness, or the low rez, or the maziness of the levels on its own would probably be fine, but all three combined is a bit too much, I think.
I played it through 3 times and got 3 different endings. Two were obvious losses/deaths, so it makes sense that they ended abruptly. But I also got what appears to be the "good ending," and it also ended kinda abruptly and anticlimactically, without totally explaining everything. A bit more closure would be nice. But you did a good job of providing clues as to how to get there.
(Also, with a bit of backtracking I managed to get past the door that someone was hiding behind in the docked spaceship, and there was nothing in there. I assume this is a bug?)
Overall, I had fun! Nice classic dungeon crawler experience.