It has a really good gameplay, it has simple mechanics and a lot of replaybility
The art is nice, it reminds me of old arcade games
The music fits with the instruments but the melody sound more like a kind of castle music, sort of, it gives that feeling, and the sounds fit as well too
The fliping mechanic can be abused at first, but later on where there are many enemies is kind of hard to do so, and the shape shifting inside of the level it's a really unique idea, it really makes you think about the shoots you are going to make inside because there may be a lot of enemies outside and if you get inside, you may die because of your own bullets
It's a pretty good game, and counting that it was made in a game jam, its just great!
Keep working and keep it souled!