Games like TerraTech Legion
Games like TerraTech Legion include Megabonk, Deep Rock Galactic: Survivor, Brotato, Soulstone Survivors, and BALL x PIT. We matched them by the tags players give TerraTech Legion on Steam (Bullet Heaven, Action Roguelike, Vehicular Combat, Bullet Hell, and Crafting): closest matches first, and among equally close ones the better-known games.

Megabonk
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Deep Rock Galactic: Survivor
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

Brotato
Shared: Action Roguelike · Bullet Hell · Bullet Heaven

Soulstone Survivors
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

BALL x PIT
Shared: Bullet Hell · Action Roguelike · Roguelite

Rogue: Genesia
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Nova Drift
Shared: Bullet Hell · Action Roguelike · Bullet Heaven

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Roguelite

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Roguelite

Vital Shell
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

The Spell Brigade
Shared: Bullet Heaven · Bullet Hell · Action Roguelike

Risk of Rain 2
Shared: Action Roguelike · Third-Person Shooter · Roguelite

Yet Another Zombie Survivors
Shared: Bullet Heaven · Action Roguelike · Roguelite

Death Must Die
Shared: Action Roguelike · Bullet Hell · Bullet Heaven

Tower of Babel: Survivors of Chaos
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Arms of God
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

20 Minutes Till Dawn
Shared: Action Roguelike · Bullet Hell · Roguelite

R.I.P. - Reincarnation Insurance Program
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

Crab Champions
Shared: Action Roguelike · Third-Person Shooter · Arcade

Nordic Ashes: Survivors of Ragnarok
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Grind Survivors
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Time Wasters
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Vampire Hunters
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Magicraft
Shared: Action Roguelike · Bullet Hell · Roguelite