Big content update coming at you. I've replaced dungeons, which seemed mundane and a rather stale copy of combat, with the endless tower!
Climb up to floor 100, one floor at a time

Each floor has progress that fills over time while you fight through monsters. A secondary bar tracks the current enemy's health, worn down by your weapon.
Reaching 100% floor progress summons a boss with much higher health. Beat it to ascend a floor - lose and the floor's progress resets.
Every floor rolls a random set of modifiers (Burning, Frozen, Cursed, and others). A weapon's prefix can counter a modifier's penalty and turn it into a small bonus.
Monsters hit back while you fight them, and defeating one heals a portion of your health, so gear quality directly affects how well you hold up over a floor.

Weapons and loot

Weapons drop with a randomly rolled condition, quality (rarity), prefix, base type, and suffix, all of which affect DPS and gold value.
Rarity is shown throughout with distinct colors per tier
The equipped tower weapon appears in the Weapon slot on the Equip screen and contributes to Combat skill speed.

Crafting

Keep up to 5 weapons in a stash for crafting
Reroll a stashed weapon's prefix, base, suffix, and rarity using Arcane Dust. Add a rune to bias the reroll toward a matching prefix family (for example, a Fire rune favors Burning or Blazing prefixes).
Each weapon has a limited Potential that is consumed (a random amount, capped at a quarter of its total) on each reroll. Once exhausted, the weapon can no longer be rerolled.
Legendary Worldheart Gems raise a weapon's condition by one tier at the cost of all remaining Potential.

Other additions

Robot parts: rare drops that, once you've collected one of each, assemble into a machine follower that boosts your DPS.
Artifacts: equippable tokens (up to 3 can be equipped at once) that grant bonuses such as increased attack power, bonus gold, or extra loot.
Treasure chests: accumulate up to 5 over time, whether playing or offline, and open them to receive a batch of loot.