Personally, I think adding self-heal to the first enemy in a game is a bad move- especially with such a low damage floor. It'd be better, at least, if it was a multi-move action. LOCKING BACK UP should *definitely* be a multi-move action. Encountering/using a move for the first time should should the move for a few seconds- it's frustrating to try a new move, and waste an entire turn because you didn't know it'd be three clicks immediately after it fades in. Better yet, move the enemies up, and make the bar always visible- that way you can see the required QTE for a prospective move. Giving everything such a wide range, with such a low floor, is intensely frustrating- am I going to deal 1 damage every attack for the next 5 turns? Is the Penetrate move going to hit me even if I'm in the square? Are they going to immediately heal themselves afterwards? I think it'd be better to have a higher floor. It might even be psychologically better phrasing to say '1+1-3' than '2-4'; that way the base damage seems to be 1, and the RNG is more of a bonus. But that's more subjective. If a staggering chasm of a range is absolutely necessary, it might be better to swap out for just the crit system- normal, consistent damage, and high spikes. *Preferably* where the player knows ahead of time- perhaps occasionally selecting a random move, and buffing its stats if you choose that specifically. The upgrades are also quite opaque, until you've chosen a few- it'd be nice to show the buff before you click. Praise: the art's nice, of course. Tucking Unlock out of the way until it's taught is good. Streamlined menus, easy controls.
Edit: I think the inconsistent-seeming hitbox size could be from the bar still moving after input is given. It'll barely enter the box for a 0, and will have just barely left the box for a 1.