Pretty cool idea! So let's dig into this one. My main issue with this is that the gameplay itself is quite shallow. It boils down to just micromanaging two buttons, upgrading your resource gathering, and then sending out troops to delay the ship a bit so you can have some time to get more resources. It's actually quite simple to win. If this idea is expanded a bit further I would suggest adding some additional depth to the gameplay so you can put a bit more thought into your actions, but your current implementation is perfectly fine as a prototype!
Also, a minor gripe, but using the mouse to click on the pause menu and then needing to swap to arrow keys to traverse the menu was a bit inconvenient. It would have been nice if I could purely use the mouse for everything.
That aside, I do like that you added pause functionalities and the ability to disable the sound, it really makes the game feel a lot more polished. I actually smiled a little when I saw that you included those features. The presentation overall is quite good and the visual style is quite cool. However, I think the music could use a little bit of work. Overall though, great entry, and good luck on the jam! :)