Nice, interesting concept with a good feeling of progression. A few suggestions:
the dungeon screen doesn't update with how many enemies you've defeated unless you turn on or off autofight. Along with introducing exploits that are very easy to pull off accidentally, this generates a lot of confusion early into the game and makes it harder to gauge progress. It should instead update whenever an enemy is killed.
waiting is a core component of idle games, but you could double or triple the speed of encounters without losing anything important. You're still dealing with thousands of encounters. I'd recommend decreasing the delay between gaining currentSpeed for both you and the enemy.
I'm coming at this from the perspective of a big fan of games like The Prestige Tree. On that note, I really appreciate the "calculation" section of the stat descriptions. I gave this 4 stars, but I couldn't copypaste this critique from notepad to the rating section, so I put it here.