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