We kind of had the same ideas; I made a wave-based shooter, too!
https://itch.io/jam/game-off-2020/rate/819760
RED ROVER is a top-down shooter, though. Aliens uncloak all around a rover with express intent to destroy her, so she tears them all apart and collects samples from their carcasses (collecting samples is, after all, her job). I hadn't made an action game before, and the last time I used Godot the end result was janky as heck.
This one turned out better. But is it good? That's for YOU to decide!