I can’t recall a gaming villain who looks as imposing as Reaper of Souls’ Malthael but leaves so weak an impression. He pops in and out as the narrative unfolds, spouting a few threatening lines before evaporating in a mist of gloom, and thus he recalls Blizzard’s similar treatment of Arthas Menethil during World of Warcraft’s Wrath of the Lich King expansion. But at least Arthas had the benefit of years of accumulated lore to support his cameos. The star of but one act, Malthael is never around long enough to make us care about his grumbles.
The new Transmogrification system, a World of Warcraft import, ensured that my Crusader always looked rightfully awesome by letting him adopt the look of preset models or Reaper’s legendaries.
Adventure Mode is almost rebellious in its freedom: it lets you access all five acts (even if you haven't played them) and battle through them with level-appropriate enemies at your leisure.
A new Mystic NPC that lets you swap out a single stat on an item for a randomized new stat fills some of the void left by the auction house, but high resource costs and randomization seem to keep any exploitation in check.
All of this combines to make Diablo III both an apology and a love letter, the game it should have been all along.