Cool mechanic and cool take on the theme. I really like the idea of the players weapon being something that rotates around them, and could think of a lot of things to do to expand on that (for example, giving the player some level of control over it might be interesting, especially against a wider variety of enemies).
The art felt a little all over the place in terms of style of pixel density, although the player sprite is pretty neat looking in a goofy way. I also feel like this is one where it would just really benefit from more going on. The UFO enemies felt a bit tedious, and the alien enemies were comically nonthreatening. Of course, this is all understandable for a jam (and a first at that!), just some things to think about if you plan on expanding this.
Overall, really neat. The game dev in me can't help but think of ways to run with this concept, which is a sign that you're really onto something in my opinion! Great work!