There's a lot to like abou t this game. The ps1 shaders are implemented well, the music and sounds are good and I quite like the idea of getting a boost from damaged.
I think the biggest area of improvement is the player controller, it feels somewhat slow in my opinion and I don't understand why there are two inputs required to dash and to double jump. Stopping the game for that split second adds just that tiny bit of jank and makes it harder to get into a nice flow. It also makes me wonder why it's impossible to dash when grounded.
Other than that, great work!