This is kinda cool! It was super not intuitive and did take me a while to figure out how to even play, but the mechanics underneath seem like the start of something. Usually when designing a game (especially for jams) it's easier for a player to understand simpler (and clearly communicated) mechanics. This is a whole artform so I'm not going to be delving into this, but it's something you can learn by watching a lot of gdc talks, make a lot of prototypes but most importantly playtest. Have someone play your game and sit by their side, silent, and just observe what they do. Maybe ask a question or two like "why did you put that building there?" or "why did you pick that card?". It's really just understanding how players think. When I make a game there is a lot of time spent on testing it and then doing things to "hint" players in the right direction. Or just in general make it easier for them to enjoy the game. For example, in this game, the toggling of the UI is confusing, and it would be simpler if it was just on the entire time. Or at least on by default.
Again, I think you have a decent elevator pitch here "repair the defenses on your ship", but there is still a bit to go before it will feel good to play. That comes with a lot of experiementation. So keep at it!