I am not sure if the developers read this forum, but I would like to suggest one small improvement to this game.

Whenever you have cleared a stage you should automatically advance to the next stage. Currently you still have to move all characters to the right of the screen which is a bit tedious.

I think the reason that this doesn't happen is that one of the classes has an upgrade that can let them heal allies. If you automatically advanced to the next stage when everything is clear, it could mean losing a good opportunity to heal.