Hi, I'm a new Hammerwatch player and last night I played through most the game with a few friends. Typically I wouldn't offer input with such little experience, but there is one thing that really stood out as an issue to me. It is the design of the Paladin's Heal ability. As soon as my friend unlocked it and bought it last night, the first thing he said was "I'll try my best not to cheese this."
This is because we all knew that we had the sudden ability to heal to full HP between every wave if we were willing to wait for the Mana Regen. Even though we actively tried to ignore this possibility, there were times when we were out of lives and low on Health, and we just couldn't afford not to abuse the ability. I feel the tension of having a low health party moving into a deadly room is one of this game's greatest qualities, but that tension is completely undermined by the Heal ability.
From what I understand this ability will be later moved to Priest (which I think is a good idea) but even then I feel the possibility for unlimited healing, even if players choose not to abuse it, will give a sense of safety at all times. I love the challenge and pace of this game, and I hate to see that wasted by an unlimited heal that totally distorts the pace.
My suggestion for Priest would be to somehow limit the amount of healing they can do, but in turn make it so it is very effective. Maybe Priests don't regen Mana, but they get Mana back whenever the team picks up money. This way their healing will be effective as long as the team continues to make good progress, but the healing will taper off if the damage the team takes outweighs their progress. If you don't like the idea of changing core mechanics for them, maybe they could get a healing bar that fills up through different actions. Or perhaps they could use their own HP to heal, so you could keep fueling heals as long as you pick up all the foods and manage some Combo Healing. Just a few ideas.
Really, this is a fantastic game that will likely get a lot of replay in my circles. I'd just hate to see us have to ban the Priest because we're the type of gamers that don't want to cheese through challenges.