Quite the short but sweet point and click adventure! It's unfortunately a bit short, especially if you just knock the book over and hit the button immediately (like I did on my first try) but the game does have a great amount of depth to it with a huge amount of dialogue and other interactables that intrigued me and made me want to go back and see what other routes and information there was to discover. Couple that huge amount of depth with the stylish presentation and interesting use of the rewind mechanic as a diegetic superpower of our character (or so it seems to imply), and I think this does a wonderful job at serving as a demo/prototype for the main game: consider me intrigued and wanting to see how this shapes up in the end!
In terms of feedback and potential improvements:
1) If you hover the cursor over the book on the right hand side, you can't read the pop-up text to 'pick up' or 'examine' since it's to the right of the cursor and it therefore spills off the screen. Hopefully it can be updated to make it so that text is always visible, perhaps aligning to the left if the cursor is close to the right side of the screen.
2) Might just be me being dumb, but some of the visuals were a bit too dark or confusing for me to tell what was going on. I didn't even realize there was a pit at first, and I don't know exactly what the bookshelf is doing by knocking it over: it says it is making a bridge but it doesn't look to be going across the whole pit, only half of it, so I don't know why it isn't sliding down into it or something akin to that. Also couldn't parse what was going on when Hank hits the button and the cinematic plays: looks to me like he just lands in the pit and the bookshelf bridge is nowhere to be seen. Also, how the heck are we throwing the book and such if we're in a straightjacket?
3) It might be asking too much, but there were some silly inconsistencies in the dialogue if you interact with it at weird times that I'd love to be addressed. For example, if you decide to ask about the gun after you've already knocked the bookshelf over, the villain says something akin to it being an insurance policy if you find a way out of the pit, but by knocking the bookshelf over, he's already acknowledged that you've found a way out of the pit by doing so. Maybe lock that dialogue interaction from happening if you're knocked the shelf over, or update the dialogue for the two different times you can ask it during? It's a lot, but it'd be a great touch to have that amount of reactivity and consistency.