The glitch effect to cover the empty black of the out of bounds is biliant.
I love the wobly effect of hit enemies and the feel of the hammer when it hits.
Being slowed down when i get shot is a little bit frustrating since i have to get close to hit them.
The normal jump (the one in bounds) feels a litle too short sometimes, you could play with its height velocity and think about the low gravity to make more vertical levels (maybe a boosted jump out of bounds?)
Keep the experiment alive, this is a little gem.
With a little narrative it could become something revolutionary.
You could also make it meta idk, you are literally breaking the "fourth wall", it could be an interesting starting point.
Also the dev comments could fit this narrative, you could use them as a clue to guide the player.
It could become an horror or an adventure game with an out of bounds entity that must be eliminated, just saying : ^) )
Keep on keeping on <3