Interesting concept. It's kinda strict with how you have to play. La+ only one who can do anything useful. I would make that you can level up others. Also would be great if you show pebble's travel distance.
Totally! Yeah, if I expand this into a larger game, I'd like to make more than just La+ retain her experience. By the way, you can click on the pebbles to show/hide their travel distances!