I won for the first time several months ago and I'm still amazed at how quickly progression came after that. The next few times you win you may not make it back up with the amulet, but once you do almost every time you make it past level 10 or so you'll make it all the way down and back up again.
Yeah, this game is really just a learning curve. Took me 80+ runs to get a w, and now without challenges I win about 30% of the time.
I've been struggling to get a win with 6 challenges though.
Badder bosses isn't hard, it just requires more strategy. For slime, you always need to be able to duck behind a corner in a single turn, so you can loop the boss around a single tile of grass to achieve this. Tengu just have a blink stone or two. Caves boss isn't much harder, neither is dwarven boss. For the eye, just kill the spawners before starting the boss fight and study the description of each fist before making a move.
Swarm intelligence just makes it so you get swarmed when entering a floor for the first time, after that the floor gets easier to clear.
Hostile champions does add considerable difficulty, so don't go for that one first.
Forbidden runes is pretty easy to work with, so is into darkness.
Barren land is easy as well, you just don't get the extra healing from dew drops and sunflower, so just craft any sunflower seeds you get into heal pots.
For what to not do, pharmiciphoba is Uber hard, so is faith is my armor. On diet is hard in combination with into darkness and barren land, so I avoid it.
"Into Darkness" was the first one I won with. If you conserve your torches the first several levels, it isn't much different than a run with no challenges.
I have been trying to win one game for each class, and it took me forever to win with warrior and have not been able to with mage, but I don't want to skip mage before going to next class.
I did that too, and mage ended up being the last one I won with. Ironically, I think I ended up leaving his staff with magic missile that run because I ended up with a ton of wands, so I could buff all of them at once at will by using my staff.
Fun fact: you only have to buff the first zap of a Wand of Warding, then you can zap the ward with normal zaps to upgrade it. It'll be a powerful ward, assuming you have enough charges to level it up significantly.