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