I did like the idea of the circular movement around the object to protect, it adds flavor to the game. You have to be careful with it though. because of the frame shape, it means enemies coming from the left or the right can be hard to react to, while you have plenty of time to react to enemies coming from a corner of the screen. One way I know how to circumvent that would be to add indicators showing where off-screen enemies are coming from, making any direction that enemies can attack from equal.
The hitboxes for the enemies are unintuitive, and sometimes I would clearly connect with the enemy sprites, but not damage them.
I think one of the weakest points about the game is that the art style is inconsistent. I really liked the UI buttons sprite, but when you compare it to the enemy sprite or any other asset, it looks like its from a totally different game.
The idea is there, and the game would benefit a lot from more content, like an upgrade system, and other enemy types (like others mentioned).
Others mentioned the shooting and how it would be better to be able to control it. I will add that being able to control the fire gives room to unlimited possibilities of features, so just keep that in mind.
Fletching out the story would also be very cool, the story kinda doesn't make sense. You should also try to be aware of English spelling and structure errors when writing a story in a game.
Anyway, well done on contributing to the Game jam!