Cool game! If you add some more content, upgrades etc. that would be a nice base for a game.
I love the aesthetic with limited palette, looks great and everything is clearly visible. Music fits well, some sfx would add a lot to the UX.
At first I wasn't sure what to to, but first waves are well balanced to give player time to figure things out. Then I noticed that cursor sometimes changes to X, so I though that this is for shooting enemies. But then realized it is for moving units. Some kind of tutorial, even a game screenshot with UI elements and some text explanation would help with that.
Managed to complete the game on 3rd try, after figuring how things work.
Enjoyed it a lot and I hope to see an update post-jam :)