A good start
Like you said, its still in demo form, but a good thing i would like to see is...
1. More characters
2. Less OP overdrives (me and link killed shadow in two turns)
3. A music selection (like 3 songs to choose from)
4. Shorter credits (or a fast forward button)
5. The "Play Again" button replays the credits, not sure if that was on purpose.
6. A save feature, when you get everything done, is useful, too.