Games like ArchMMO 2
Games like ArchMMO 2 include Last Oasis, Notes of Soul, Warframe, Gloria Victis: Medieval MMORPG, and Neverwinter. We matched them by the tags players give ArchMMO 2 on Steam (Massively Multiplayer, Action, RPG, and Indie): closest matches first, and among equally close ones the better-known games.

Last Oasis
Shared: Massively Multiplayer · RPG · Action

Notes of Soul
Shared: Massively Multiplayer · Action · Indie

Warframe
Shared: Action · RPG · Massively Multiplayer

Gloria Victis: Medieval MMORPG
Shared: Massively Multiplayer · Action · RPG

Neverwinter
Shared: Massively Multiplayer · RPG · Action

The Elder Scrolls Online - Standard Edition
Shared: RPG · Massively Multiplayer · Action

Touhou Big Big Battle
Shared: Massively Multiplayer · Indie · Action

Bastion
Shared: Action · Indie · RPG

Hades
Shared: Indie · Action · RPG

Dust: An Elysian Tail
Shared: Action · Indie · RPG

Farever
Shared: Action · RPG · Massively Multiplayer

Project: Gorgon
Shared: Massively Multiplayer · RPG · Indie

Blue Protocol: Star Resonance
Shared: Action · Massively Multiplayer · RPG

DRAGON BALL XENOVERSE 2
Shared: Action · Massively Multiplayer · RPG

Citadel: Forged with Fire
Shared: Massively Multiplayer · RPG · Action

Hades II
Shared: Action · RPG · Indie

Onset
Shared: Massively Multiplayer · RPG · Action

Hero Siege
Shared: RPG · Action · Indie

The Wind Road
Shared: Action · RPG · Indie

Black Myth: Wukong
Shared: Action · RPG

Path of Exile 2
Shared: RPG · Action · Massively Multiplayer