This brings up nostalgia. As a kid I would play Asteroids constantly on my old computer, I like your variant better though, you can actually stop moving XD.
I liked this game, kind of easy and short but good, the final bosses were a piece of cake, (just shield jab, you literally become invincible to their attacks) other than that, very enjoyable!
This is a good start but its too easy. In alot of RTS games the AI gets stronger if you leave them alone for too long, adding that will make this game more enjoyable when you beat them. Good start and I hope you're sequel goes well.