This one is highly polarized toward "strong concept, weak execution."
I love that there's a ghost, which is I think an underexplored niche in sci-fi horror. People tend to shy away from the supernatural because of the genre expectation that everything's going to have a (pseudo)scientific explanation, but Mothership seems like the perfect place to explore a straight-up haunting in a sci-fi context. Maybe there's a bit too much else going on at the same time in terms of random monsters... might be better to have more encounters that are different manifestations of the same spirit.
I like that the Planet of the Apes-style twist is well-disguised. I could see players getting sufficiently caught up in the other stuff that they're blindsided by the revelation that this is Earth.
Polish is really the issue here because it's not just a matter of aesthetics, it gets in the way of usability. Formatting of the text is particularly an issue, especially in the bullet lists. The size of the indents is way too big for such narrow columns, and then it's not continued onto the next line, so you've got an extremely ragged left edge. It's even worse where you have nested lists.
There's also some lack of attention to mechanical detail. Calypso has five wounds but no hit points, so it takes exactly five hits to destroy (in a single round, or more with regeneration), regardless of whether those hits are punches or grenade explosions. It'd be weird for it to survive a single powerful assault but then die to five players ganging up on it barehanded. The "kraken wearing a submarine" sounds cool but also way too big for the setting. Outside, sure, but I think it'd stretch plausibility to have it randomly turn up in the living room.
If you want to polish it up after the jam, I'd suggest starting by thinking through the encounters a bit more to fit the theme and environment better, and after that, take the time to learn how to use the text-formatting features in whatever software you're using, and either look at some published trifolds or read some articles about pamphlet typesetting to get a sense for how to make things easy on the eyes in a narrow format.