I agree with many of the concerns OP mentions, especially the need for a variety of engaging games. The demo game feels a little too cartoony for my taste, would love to see more titles in different styles.
Another concern I have is how can it help reinforce proper posture, body positioning, and footwork? I realize this is very difficult to address, but those fundamentals are extremely important and seem to me to be areas where many beginners could develop bad habits if not corrected somehow.