Thanks for the feedback, I'll address those items today:
1) Yeah, i haven't gotten to that yet. I'll work on that today. I just added the zombies taking damage yesterday.
2) I kinda wanted it that way. I wanted jumping to feel like a Tactical Decision, like in old Castlevania games. But... it's clear that isn't very popular. I'll tweak the numbers to instead make it more responsive, and less delayed.
2.5) As for the full-height jump, again, pulled from Castlevania, but also Mario. Maybe I need to go back and study those games more. Previously, in my other game MiniMon, I attemped this mechanic, but it wasn't quite right, and I ended up scrapping it. I think I need to create some more enemies/obstacles before I can scrap this one. I'll definitely study how games like Megaman and Metroid etc deal with it, but... If I have to scrap it for this game... maybe I'll get it right some day with another game?
3) AGAIN, like Castlevania. lol. However, even in Castlevania, the Knife is a quick weapon. I'll speed it up.
4) Yup, I am looking through software now to replace the chiptunes I usually use. The game will have sound before the Jam completes.
Once again, thank you very much for taking the time to write up all that feedback! It's very easy to get stuck into a mindset of what's fun for me, and not necessarily what's fun for others.