Glad the Comment Pact Club gave me this game to check out, I love tower defense games!
The 3d models included in this were top notch! If they were all made within the jam time that's super impressive, with a little better texturing on some of the enemy ships, some of these models would quite easily fit into a similar 3D TD game like the Defense Grid series.
The music and audio were all fine for a jam game too. I was a bit sad when the game ended after wave 3 (maybe something else happens if you finish wave 3 with full health but I'm not sure) but of course I understand the constraints of working on a game for a 4 day jam, I made a game in Unity too (wasn't too happy with it in the end due to being a lot shorter than planned) and I understand sometimes we have to cut things we don't want to to finish on time.
Hope to see more games from you in the future!