Very good mod indeed, excellent quality.
Atmosphere, riddles, level design is all top notch from what I was able to see. I had to give-up in level 4 (after roughly 10 hours playing!) because a particular fight (that one cannot avoid) proved too hard for me and my party (started the mod with a new party on normal difficulty). Running the mod in easy difficulty might help with that particular fight but also makes all other fights up to that point too easy.
I think I just miss the quick reflexes and the hand-eye coordination necessary in that fight, looks like it involves juggling with potions/scrolls/bombs during a fight, something my fingers just can't do.

But the 10 hours I got out of the mod have been an excellent experience. My thanks to the creator.
It's the testament level of course - the Sea of Flesh first (Got past it with no fighting, using the snails as defense) and then the Elemental rooms ... was unable to survive a single room for longer than 20 seconds and there are 4 of them with no access to a crystal - I have no idea how people manage to get past that (and some even manage it on hard difficulty from the posts here in this thread - incredible!). No idea how they do it.
Tried everything I could think of: the bolts, bombs, potions, trying to disable the traps, moving around or not moving at all, no dice for me.