poor tutorialing
Actually I love this game being so terse. It allows you to learn it yourself. However some moments are really unobvious, like the inventory and trinkets ( items indication as blue light is too vague). The most big problem for beginner is to master "lightplay", it took me a dozen of runs to fully comprehed how light works.
"turned into a death machine at the 13th level and game becomes a piece of cake"
Hehe, I just love to break games by looking flaws in its balance, it's kind of my hobby, I am veteran of roguelike and roguelite games. You see, 5 strength/technique points already doubles your damage which is extremely huge bonus, making fights with angels, minotaurs and devils much easier, especially with the help of backstabs. Energy stat is also extremely overpowered, 10 points in it make you already fight relentless due 20% recover by kills. I would make this bonus 5+LEVEL% of missing energy instead of maximum one. Other skills are fine though. Also I love using spear-like weapons, they seem to be imbalanced in my opinion, long reach doesn't allow enemies to get closer. (Still I get owned by... cactuses? They seem to be the most tough enemies, it's scary to approach one in a corridor)
I was also thinking of removing the Bell from the starting zone
In my opinion bell doesn't give that much in the starting zone though (It gives power depending on the amount of enemies in a zone, right?) However in other branches it can spawn right at the exit and give you +15000, or sometimes it's impossible to find it at all.
Did you know? This game has an end!
Nice, I suspected it. There are obviously different dungeon stages which progresses further but I usually never left 5x5 square (2 rooms horizontal and 2 vertical) to safely allocate power. It was very nice to make them distinctive also. North seems like some tower, South is some dungeon and West is absolutely dim lit cave. I like it, especially that these directions have their own enemy types and special rewards, like the flowers that cure your curses which are growing in the West. (but West is extremely dangerous due lack of light so you should go there with some light artifacts or make some tricks with your spells)
However, you should really give some indication on this. Some players will probably think that there is no progression in the dungeon.
Once again, it's your decision how to make it, if you think that the level progression is fine then leave it as it is and polish some real flaws. Despite its faults, it's still extremely good quality game. I'll be looking forward to 1.00 and would gladly play it (or even buy it if you consider putting this on some store)