I won my second game, as a barbarian. Some comments on game design:

1. Charms are great! (But I haven't seen them enough.) This was the first game where I got a charm, which gave +2sp, which I put in my ranged slot. I'm not sure it made me stronger, but it changed how the game played a lot, and it was very fun. I'd consider giving some characters a starting charm, for example mages for +mana, or barbarian for +sp.
2. Strafing is very fun, but I find it pretty hard to predict who will be hit when. It would help me as a player if hovering over a tile with the mouse highlighted the enemy that would be hit by the strafe attack (if there is one) and the weapon that is used (if there is one). (That last part mostly because I still remember how as a Ranger I'd keep hitting enemies with my bare fists.)
3. Finding an altar of strength as a strength-based character was deliciously OP. I sold most of my spare equipment to buy Strength points (and a few potions for the final boss).
4. The books of knowledge where you get a free talent point in the skill you pick work really well to make me try out new abilities and combinations.
5. Shadow Step was very nice, and makes me see what the teleport abilities of the mage classes could be. I don't see much use for those abilities as they currently are. Perhaps if they were free once every 20 turns (or once every level-up even) I'd experiment with them more.
6. Poison sucks. I blew a few consumables fighting the boss with the poison vipers and the poisoned knife, because poison is deadly when green mushrooms aren't nearby. But I never found use for the blade. +25% chance of 200% poison is +50% damage on average, but it's incredibly hard for that damage to be useful. The mace and the handaxe were my weapons throughout the game.
7. I bought Power Strike and Cyclone Strike, which I usually don't have on a Barbarian, and they were very helpful against Grapple.
8. Playing without the mouse (or even playing with touchpad) feels impossible.
9. Could there be some kind of visual warning that a weapon won't benefit from any more stats? Maybe highlight it in gold or whatever. (Though that could also be confusing. :/ )
10. Bosses feel like they generally cost me more resources than they guard, but killing all the bosses is fun.
11. Battle axe (2Handed, 6 more damage than handaxe) feels like a extremely bad deal. Perhaps that was only because I had a +2 shield of reflection.
12. At the end of the game, I probably should have used my Wand of Fire to charge up my Molten Forged Boots. Finding fire damage is hard, and the wand scales poorly.
13. Life tap saved my life when I was fighting a swarm of fire bats (or at least meant I didn't need to use consumables)
14. The Core is a very scary branch, even with 70% fire resist.
15. (Not related to this character) Fireball 2 feels sucky. +6 damage in the center, when previously it was +4 damage everywhere, and on plain fireball I mostly use the edges of the fireball in the first place. Maybe it it also provided a 1-turn stun in the centre square... (no that would probably be OP, stun-locking bosses and such).
16. It would be great if there was a key for 'attack melee if possible, otherwise attack ranged if possible, otherwise wait' (or if Q could be configured to do this)

and a second win with today's game of the day. Very similar build; apparently this build suits me.