I'm not exactly sure how early that demo is supposed to be, but since you're not calling it an alpha or proto, but
the demo, I'm a little concerned that you're assessment of it thus far is somewhat rather generous. Allow me to list my qualms with the demo as it stands.
- First, there is a long pause prior to each appearance of the "GO" sign.
- I can fall off the level.
- There's a whole lot of moves missing, including all hand-to-hand grappling moves (or whatever they're called; grabbing enemies and throwing them backwards or hitting them on the spot, etc.).
- No jumping, or that I found.
- The level is incredibly short, yet I've seen screenshots of several levels.
- Enemies do next to nothing, and are too easy to beat.
- No timer-based movement. The yellow guy animates way too fast.
- Boxes don't seem to behave right when broken.
- I can see through the black parts of building textures.
- The character looks rather skinny, and very little like Axel.
- The fire spouting from one of the buildings is more like orange smoke.
- Character animations are nice, but he "floats" along the ground if you attack while moving.
- Game freezes and music skips over itself prior to level end theme.
Basically, there's a whole lot of stuff missing here, and I think it's way too early to release a demo. It's playable, yes, but not enjoyable, and I can only assume that several of the points I've raised you already know, making it difficult to give any useful criticism.