Three issues I’ve run into: (playing on Windows 7 v0.8.6 if it matters):
First, I’d suggest changing the healer’s default ‘Both’ behavior to casting the highest-level spell that has a current valid target. The current behavior, by contrast, allows a ranged enemy beyond the reach of a charged-up Zeal to pick away at an ally within healing range. You might also treat Zeal as an always-cast-if-available spell rather than waiting for an enemy in range, since it can benefit even totally healed allies.
(Edit: this doesn’t seem to be as simple as it at first appeared…under frustrating difficult to replicate circumstances, a healer will just sit there with a wounded ally in range and do nothing to help, even when Heal is prioritized…will try and nail down exactly when, but this marks at least the fifth occasion. Changing priorities to something else often breaks his ‘trance’. even changing to ‘fight’ if healing is desired.)
Second, unless this is part of the joke, isn’t the monstrous hand in the boss battle a LEFT hand? (how sinister!)
Third (and I have seen this behavior in the Flash version as well), there’s a minor glitch in the naming system. Suppose I name Berserker 2 Bob when he is first created. Later on, I decide that Bob is a better name for Berserker 3. So first, I change Berserker 2’s name to Aloysius. Now, I attempt to change Berserker 3’s name to Bob, but it tells me I can’t, because there is already a berserker named Bob. This persists after reloading.
Nitpicks all, but better to say something than not, right? 
Thanks for the great game!