Games like Tetraphobia
Games like Tetraphobia include Hades, Hades II, The Binding of Isaac, UnderMine, and The Binding of Isaac: Rebirth. We matched them by the tags players give Tetraphobia on Steam (Indie, Action, Action Roguelike, Roguelite, and Dungeon Crawler): closest matches first, and among equally close ones the better-known games.

Hades
Shared: Action Roguelike · Indie · Roguelite

Hades II
Shared: Action · Roguelite · Action Roguelike

The Binding of Isaac
Shared: Indie · Action Roguelike · Action

UnderMine
Shared: Action Roguelike · Roguelite · Indie

The Binding of Isaac: Rebirth
Shared: Indie · Action Roguelike · Roguelike

Megabonk
Shared: Action Roguelike · Indie · Roguelite

Vampire Survivors
Shared: Action Roguelike · Roguelite · Indie

Skul: The Hero Slayer
Shared: Indie · Action · Action Roguelike

Cinderia
Shared: Action Roguelike · Roguelite · Action

Gunfire Reborn
Shared: Roguelite · Indie · Roguelike

Shape of Dreams
Shared: Action Roguelike · Roguelite · Action

Heroes of Hammerwatch II
Shared: Action Roguelike · Action · Dungeon Crawler

Moonlighter
Shared: Roguelite · Dungeon Crawler · Action Roguelike

SYNTHETIK: Legion Rising
Shared: Indie · Action · Roguelite

Dreamscaper
Shared: Action Roguelike · Action · Indie

Dungreed
Shared: Action Roguelike · Action · Indie

Enter the Gungeon
Shared: Action Roguelike · Indie · Dungeon Crawler

Nuclear Throne
Shared: Action Roguelike · Indie · Action

Yet Another Zombie Survivors
Shared: Action Roguelike · Indie · Roguelite

Streets of Rogue
Shared: Action Roguelike · Roguelite · Action

Tiny Rogues
Shared: Action Roguelike · Roguelite · Top-Down Shooter

BALL x PIT
Shared: Action · Roguelite · Action Roguelike

Rogue Legacy
Shared: Indie · Action Roguelike · Action

Wizard of Legend
Shared: Action Roguelike · Dungeon Crawler · Action