Deepest Dark says: You ain't ready for me.
So after much delay I'm working on Deepest Dark 2.0. It will refine and enhance the difficulty even further, change enough that even if you tried the earlier versions you'll still be surprised, and will also revise the skill system so that it's more interesting and dynamic on the hero side of things. It will also advance beyond the tutorial region, Cunavern and beyond which is kind of important.
It is still in testing as of the time of this posting but it is going extremely well.
Key differences apparent early game by this point:
Gaulen learns Wounding Strike (and Bleeding Strike).
Thieves also learn Bleeding Strike.
Arcane Soldiers can equip and train Daggers, which have been substantially buffed.
Paladins can equip and train Axes.
There's no multiclass penalty on skills (I might readd a lesser one).
All of the combat and semi combat classes start with 2 ranks in weapon skills instead of 1 (it still costs 2 skill points per additional level for them).
Most low level spells (not skills) have had their skill point and/or mana point costs reduced.
Many underpowered skills had their skill point costs reduced.
Every class gives a few starting items, not just Explorer and Thief.
The following classes get 1 additional skill point per level: Cleric, Thief.
The following classes get 2 additional skill points per level: Divine Summoner, Explorer, Mage.
Mana stat gains for most classes have been changed. Instead of every class gaining mana based on energy, each class has its own stat
Barbarian, Soldier: Strength.
Arcane Soldier, Bard: Agility.
Explorer, Thief: Speed.
Paladin: Constitution.
Cleric, Divine Summoner, Mage: Energy.
(this is experimental and might change)
Many more enemies have defined strengths and weaknesses, making having a wide variety of abilities useful.
Enemies hit significantly harder and are just statistically more capable all around.
All weapons have increased critical hit rates and decreased critical failure rates. The biggest gains are on swords and daggers.
There are many more changes but they don't become apparent until after the Rat Cave.