Games like Star Vortex
Games like Star Vortex include Warframe, Borderlands 3, Borderlands 2, OUTRIDERS, and Last Epoch. We matched them by the tags players give Star Vortex on Steam (Action RPG, Looter Shooter, Building, Loot, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Warframe
Shared: Looter Shooter · Action RPG · Online Co-Op

Borderlands 3
Shared: Looter Shooter · Multiplayer · Loot

Borderlands 2
Shared: Loot · Looter Shooter · Multiplayer

OUTRIDERS
Shared: Looter Shooter · Loot · Multiplayer

Last Epoch
Shared: Action RPG · Loot · Multiplayer

The First Descendant
Shared: Looter Shooter · Multiplayer · Online Co-Op

Diablo® IV
Shared: Action RPG · Loot · Online Co-Op

Torchlight II
Shared: Action RPG · Loot · Online Co-Op

Tiny Tina's Wonderlands
Shared: Looter Shooter · Loot · Multiplayer

Path of Exile
Shared: Action RPG · Loot · Multiplayer

Tom Clancy’s The Division® 2
Shared: Looter Shooter · Multiplayer · Singleplayer

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

Borderlands 4
Shared: Looter Shooter · Action RPG · Loot

Cosmoteer: Starship Architect & Commander
Shared: Building · Singleplayer · Sci-fi

Wolcen: Lords of Mayhem
Shared: Action RPG · Singleplayer · Loot

Warhammer 40,000: Inquisitor - Martyr
Shared: Action RPG · Loot · Action

Risk of Rain Returns
Shared: Multiplayer · Looter Shooter · Online Co-Op

Grim Dawn
Shared: Action RPG · Loot · Singleplayer

Terraria
Shared: Multiplayer · Building · 2D

ELDEN RING
Shared: Action RPG · Multiplayer · Singleplayer

Wayfinder
Shared: Action RPG · Loot · Online Co-Op

UNDECEMBER: The Farside
Shared: Action RPG · Multiplayer · Loot

Where Winds Meet
Shared: Action RPG · Singleplayer · Multiplayer

Enshrouded
Shared: Multiplayer · Online Co-Op · Action RPG