Here is the full list of all 25 Diablo IV achievements.
Reach Level 50 with a Hardcore character.
Acquire 10 Caches of Chaos from the Tree of Whispers.
Kill 50 enemies in Werebear form and 50 enemies in Werewolf form as a Druid.
Kill 100 enemies with Fire, Frost, or Lightning damage as a Sorcerer.
Kill 50 enemies while Berserking as a Barbarian.
Summon 100 Skeleton Mages or Warriors as a Necromancer.
Complete a Sacred and Ancestral Nightmare Dungeon.
Reach Level 100 with any character.
Kill the most challenging Echo of Lilith.
Imprint 10 items at the Occultist with an Aspect from the Codex of Power.
Upgrade a piece of Armor, Jewelry, and a Weapon.
Upgrade your Healing Potion to max tier.
Craft any Elixir and any Incense.
Collect 1000 Aberrant Cinder in Helltide zones.
Get 5 PvP kills.
Explore all of Estuar.
Reach Level 50 with any character.
Kill any World Boss.
Kill 666 Snakes or Spiders.
Complete the campaign.
Kill 666 Bandits, Cultists, or Knights.
Kill 666 Ghosts, Skeletons, or Zombies.
Kill 666 Drowned, Vampires, or Werewolves.
Kill 666 Demons, Fallen, or Goatmen.
Kill 50 enemies in melee range and 50 enemies out of melee range as a Rogue.