Fullscreen is fine but it cut off some region ( zoom to center while on menu, character while in game ) without that.
The character is so cute and I like this sort of art, but after that, almost nothing is playable, maybe there have some bug ?
first, no any checkpoint, I think this include in your design, but at least I can't found any on the map.
it's actual difficult to do any play test without that, because I need to restart on start position every time.
second, camera is... buggy ?
camera can not follow player if I fall down from a high platform, until I landing on the ground.
even I haven't fall, camera sometime shifted up / down while I swimming in water ( I move up and down quickly ), it make me difficult to dodge squid bullet.
and... is there any problem of character jumping height or horizontal distance ?
my character can't jump over the first squid with any "Normal" method.
but I can stick to the wall and continuously hitting jump key than it can magically climb up.
I have success to do that twice, but I don't want to test any more...
I think this is... a bug report.
I love the art and concept, hopefully to see a playable version later.