Really great map, one of the best that I've played in a long long time. Soloed to lvl 18 just now. Have to say, it was boring alone, also there was one thing that bothered me...
Terrain lacks details. It's great as it is, you've used some really nice tricks and done lot of effort to it, big big + for that. But, it feels dead, to say.
So, adding more details and some life to the world would be great

More bushes, small rocks, junk, trash, and critters. That kind of stuff.
(the portal room after Dwarf boss bothered me most, it was cool room, but just too plain)
I noticed that terrain height varies a lot, but it's not noticable because of the overview camera. But, when I noticed the height differences, they looked really great and fitted.
Items are one thing too. Better inventory system would be ideal for this kind of ORPG, 6 slots just doesn't cut it. Except if you're not planning to add anything else. Two trinkets, weapon, chest, mana and health potions are what fills the inventory currently, and it's fine if there wont be anything else.
Also, map is currently bit easy

It started to get harder now when I hit 18, but the thing that bothered me was it's basicly only hack & slash. Any chances for trigger filled boss battles?

Or then I just haven't seen them yet.
Talent system is neat! Awesome job on that :3
Overall, great map, and I will keep testing in multiplayer. This has huge potential, so hopefully you'll find time to do this!

Random screenie to the end.