I really liked the demo.
✔️ Graphics - The overall look is cohesive. Very easy to the eyes. Beautiful. There are many ways to describe how good the graphics is. I like it very much. The screen transition is really cute as well, and I also liked its color palette.
✔️ Sound effects and music
✔️ Character movement and attack - Moves smoothly and I like the variety of attacks
✔️ Level design - I only played one level. I like the design because it wasn't monotonous or boring. It was fun exploring, collecting stuff and fighting the enemies.
Minor stuff:
The default controls are a bit odd for me though, WAD instead of ASD. But that's just a minor thing that can be fixed with customizable controls. And on the tutorial decals, W and A are switched.