This is a very nice piece of work. The ambiance was well done; without any dialogue and only sound effects to be heard (for the most part) this time around it put me on the edge of my seat as to what was gonna happen next, which could've been anything.
The whole mystery of this situation in comparison to Chapter 0 has unlocked some interesting theories that I and others can only guess until you reveal the truth. People suggest this could be a reset for example, or alternate dimension. This character resembles Skoot very much, and yet is it the same Skoot as Ch. 0? He seems like he just woke into this hell too. What if Ch. 0 was really like a dream and Ch. 1 is the start of another "dream" that takes place in this same hellish world and connects with the previous "dream?" Does falling asleep start a new "dream," or something else?
The animation has improved too, it's feeling more natural than the previous chapter. I was a little iffy about his flinching to his wound. I think his arms needed to do something (move away from the wound at least, even put a hand next to it).
Your backgrounds, like in WHOOKOS, are also well done. The lighting is pretty good, especially in that hallway with the lightbulb. Despite not having played the games still, I felt more Silent Hill vibe here.
As you said this animation does feel a little short. Even though you meant to keep the pacing faster, I think for this episode part you had more freedom to share with the viewers more of this world as that has been more the focus than the character. We're just sitting in the seat of his perspective, discovering this world along with him. The parts you cut out may not have needed to have been cut out then? The intro also seemed a little confusing including the sound effects but perhaps there'll be a reason for that?
In any case I'm looking forward to Pt. 2, but first will come Zelda UO 2 and WHOOKOS 2 both of which I'm also eager for their releases.