Thank you for the detailed feedback.
First, this demo was made to show the overall concept and goal, so a lot of features are missing, such as moving platforms, enemies and other stuff found in good platformers like Celeste, Super Mario Bros. Wonder, and Super Meat Boy. After those are implemented, the actual level design will be developed.
Second, yeah I will take that advice.
Third, someone mentioned the variety of death animations before, so they're now in my development plan. However, they are a low priority for now since I want to focus on level design, which includes eneimes and hazards.
Fourth, that's not a bad idea and I want to add them ASAP, but solo development is really a hellscape you know lol