Hi Iggy.
After replying here I'll put a warning up regarding optimization. I'm aware of a few areas which are resource heavy and require a pretty beefy machine to handle.
I probably have the combat difficulty turned up way too high. It's a bit rough for new players trying to learn the game the first time around.
If you did want to try the combat again, the holy potions you collect in the mines don't just heal, but also do big damage to the undead. If you activate one and run around you can take out a big chunk of the wave, while healing your allies.
Thanks for playing!