So asides from potential boss fights, are the core gameplay features pretty much done?
Yes. I'd say what's left is bosses and special enemies (poison, moving enemies, extra fast).
Also player items with different bonuses: AoE damage, faster speed, HP bonus, armor, flanking bonus and so on.
But today I think I will work on the main menu, in-game menu, level selection screen and more tilesets. I want to make a cave with bears. I also want to make a quick "tutorial", you'll see later.
Note for later: I thought of making a puzzle level before the final level as a build-up. It would have no enemies, just object interaction. The level loops forever, the signs are all wrong: instead of going down (100, 90, 80) they show random numbers or go up. Insanity!