What a clever concept! The tutorial confused me at first, but once I got into the action, it clicked after only a few experimentation. In a way our task is to make the army destroy itself, which I find both funny in a narrative way, and fun to play as well! A strong ship can change from a dangerous enemy to a powerful asset… It just works so well! Smart idea, and cool execution.
There are some small critic I'd make about the ergonomic though. First, the red outline on enemy isn't easy to read. It could have been thicker, or use better contrast, or maybe use an entirely different symbol. Secondly, I find it odd to use the space bar for a single action, that also work like a "click" (it's targeting the position of the pointer). Maybe it could use the right click instead? That way the game is entirely playable by mouse! (or maybe I've used to much Blender and I became one of the weirdos wanting to do everything with right click)
Anyway, congratulation for making this game! It has a neat concept with a very elegant design.