Great work on this demo! I had a really good (albeit incredibly frustrating!) time getting through this! I won't rehash all the other bugs mentioned in the other comments, but I hadn't noticed anyone mention how the camera still moves when you're using a save point. It made me die AT LEAST 6 times just because there was an enemy in front of me and I was trying to save my progress but ended up looking backwards because of the menu.
Other than that, I really liked the game and thought you did really well! It didn't remind me very much of half-life 1 at all but inspiration doesn't mean copying, so I thought it was still fun. I gotta mention that staircase, though—after struggling so much with the bugs/weird enemy mechanics/insantely long elevator rides, etc., that entire staircase sequence had me questioning if the game was a serious game, or actually just a troll upload. After beating the whole thing I don't think you were trying to fool people into doing annoying things, but the only reason I didn't quit at those stairs was because I was trying to make a full recording. Maybe reconsider those types of moments for chapter 2, because otherwise it was a great start to a series, and I look forward to trying out the next installment!
I made you a Lumps Play and I hope you like it—I was a little bit harsh, but I was INCREDIBLY frustrated while trying to get through this so forgive me and keep making games! Cheers :) 🍻