The demo is pretty fun! I have to say though i am not a fan of all the instant death stuff like being smushed by the boss or the acid you got to platform across.
Like if you want it to be challenging I feel, for at least a first area, anything killing you after your shield goes down is already enough. The first boss being able to just instantly reset the fight if you dont doge fast enough feels harsh.
That's just my personal taste there, even with my gripes with that, the demo was still real fun! The art and music are amazing! You got the start of somethin great.