My favorite game so far on the jam, you nailed it. The style is great and really consistent, love the mix of a old-game feel with newer mechanics, and just the quirky nature of it all just floating in space FIST-FIGHTING aliens, how can one not love it? (also helps that its a mix of some of my favorite games, love the old-school first-person dungeon crawlers). Reminds me a bit of the indi-game: FIGHT KNIGHT, an equally odd setting where you are a fist-fighting fantasy knight.
Honestly, just at the top of my head I cant really think of any improvements/changes I would like to see, maybe there could be a place for a story-line? that could bring a bit more context too the hole thing? Maybe being able to meet some characters and interact with them etc. also, the goal itself could be a bit clearer, as your kind of just thrown in without as much as a clue at first on what to do. But really, as a isolated experience its already great.
Will test your other games after this!