This is fantastic, beautiful work. The amount of polish is insane, and it really comes through in making a fun and engaging experience. I forgot I was even playing a demo until I got into the cart and loaded to the next area. The pacing, puzzles, action, etc... was all excellent. The world was giving me great Ico vibes, and the bubble gun was very fun. 

Few things I thought about while playing:

• Some more sounds from the character as you do things might help the player feel more connected. The little intro where you zoom into the character is great and helps give a sense of who you are, but some grunts, more breathing (there's a little when you get exhausted), etc.. Would make the player feel more connected to the character, I think. Like when you die, I think the player makes a small noise. See how much farther you can go with that.
• It's a little odd that left click uses the right hand, and the right click uses the left hand.
• Enemy sounds are a bit annoying. There was a big chunk of the game where enemies were fighting or attacking me (or each other, I dunno), and I could hear their sounds right in my ear for too long. 
• There was a moment where I kicked a guy into the fire and he lit up. That was fucking great, and pretty funny. Moments like that make me, as a player, wonder what kind of crazy potential and cool stuff might be in store. Engineering situations like that might be smart.

Again, well done.

General thoughts just as I was playing:

Start menu has the start button always highlighted, where it's darker than the others.

Giving the protagonist freckles means you're a man after my own heart. 

General movement feels nice, very Supraland.

There seems to be some texture flickering on objects here, the jail bars at the start for example

Not sure if we were meant to burn the door at the start down, but arson is my default reaction to most things so that's what I did. Feels like that could at least use a tutorial.

Feel like an option for double-tapping strafe keys to dodge could also work, just as an alternative source of input.

When picking up heavy objects your turn speed can pretty easily outstrip your mouse sensitivity. Not sure what a good solution here would be, it's just awkward to control.

Some shadow flickering on moving objects.

Jumping on the chains is also kinda spotty. If you jump too high you bump the top and fall down. Continuing is easy, but I feel like... something not akin to coyote time but a sort of increased magnetism for the character towards these would go better.

Combat feels nice and snappy.

There seems to be a lot of weird lag when I hit an enemy with a firey weapon, beyond just the normal hitstop.

Blocking, pausing, then letting go of block and unpausing causes you to remain blocking.

There is a gamebreaking bug that I can't reproduce, the game might, for some reason, not let you interact with stuff.