The inventory system is hard to notice when I played the game. maybe make the slots stand out a little.
When interacting with a character I didn't know I could give them stuff from the inventory. Maybe making the slots more visible during the interaction would communicate that you can interact like that better?
No boundaries on the edges. Maybe put something there to keep the player from jumping. Or maybe have the player teleport back to the ground when they jump off.
Maybe have some levels introduce the mechanics gradually instead of having a big screen of text.
In the later levels, the gameplay becomes mostly giving NPCs stuff and using the hourWatch. Maybe an obstacle or parkour path would be fun.