Lightweight cleric is OP. Consider transferring some % of weight to her every time she uses her special to limit reset-spam. Currently you can easily cycle two characters back and forth on the weight elimination option and let the 3rd pile on the pounds, using the cleric to fuel her attacks. This takes the cleric completely out of the end of dungeon upgrade meta, leaving more available points for the others (alternating speed boosts for the two fast attackers and power for the heavy).
It would be nice to see the others characters have specials also, to add some strategy and differentiate their play a bit. Perhaps the tank could shield a character from new debuffs, or the mage could do an area attack at 1 damage.
On a more technical note I notice that click and drag isn’t working on either Opera mobile or my Wacom tablet. Are you by chance polling the mouse directly rather than using some sort of more generic onclick event?