Games like Only One
Games like Only One include Vampire Survivors, Megabonk, Death Must Die, Halls of Torment, and Hades. We matched them by the tags players give Only One on Steam (Action Roguelike, Arcade, Swordplay, Hack and Slash, and Action): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Roguelite · Pixel Graphics

Megabonk
Shared: Action Roguelike · Roguelite · Action

Death Must Die
Shared: Action Roguelike · Roguelite · Hack and Slash

Halls of Torment
Shared: Action Roguelike · Roguelite · Arcade

Hades
Shared: Action Roguelike · Hack and Slash · Roguelite

Skul: The Hero Slayer
Shared: Action Roguelike · Action · Pixel Graphics

BALL x PIT
Shared: Arcade · Action · Action Roguelike

Hero Siege
Shared: Action Roguelike · Hack and Slash · Pixel Graphics

Soulstone Survivors
Shared: Action Roguelike · Roguelite · Hack and Slash

Hades II
Shared: Action · Action Roguelike · Hack and Slash

Boneraiser Minions
Shared: Action Roguelike · Roguelite · Pixel Graphics

Shape of Dreams
Shared: Action Roguelike · Hack and Slash · Action

Moonlighter
Shared: Hack and Slash · Action Roguelike · Roguelite

UnderMine
Shared: Action Roguelike · Roguelite · Action

Dead Cells
Shared: Action Roguelike · Hack and Slash · Roguelite

Rogue Legacy
Shared: Action Roguelike · Action · Roguelite

Talented
Shared: Action Roguelike · Roguelite · Arcade

Heroes of Hammerwatch
Shared: Action Roguelike · Roguelite · Pixel Graphics

Risk of Rain Returns
Shared: Action Roguelike · Action · Arcade

Heroes of Hammerwatch II
Shared: Action Roguelike · Action · Roguelite

Deep Rock Galactic: Survivor
Shared: Action Roguelike · Roguelite · Arcade

Antivirus Survivors 2003 Professional
Shared: Action Roguelike · Action · Roguelite

Monsters are Coming!
Shared: Action · Action Roguelike · Roguelite

Children of Morta
Shared: Action Roguelike · Hack and Slash · Pixel Graphics