Games like Nightmare Vortex
Games like Nightmare Vortex include Vampire Survivors, Skul: The Hero Slayer, UnderMine, Hades, and Death Must Die. We matched them by the tags players give Nightmare Vortex on Steam (Action Roguelike, Casual, Roguelite, Action, and Perma Death): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Roguelite · 2D

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

UnderMine
Shared: Action Roguelike · Roguelite · Action

Hades
Shared: Action Roguelike · Roguelite · Action

Death Must Die
Shared: Action Roguelike · Roguelite · Action

Megabonk
Shared: Action Roguelike · Roguelite · Action

The Binding of Isaac
Shared: Action Roguelike · Action · Procedural Generation

Halls of Torment
Shared: Action Roguelike · Roguelite · Action

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

BlazBlue Entropy Effect
Shared: Action Roguelike · Action · 2D

Dead Cells
Shared: Action Roguelike · Roguelite · 2D

BALL x PIT
Shared: Roguelite · Action · Action Roguelike

Dungreed
Shared: Action Roguelike · Roguelite · Action

Risk of Rain (2013)
Shared: Action Roguelike · Action · Indie

Rocket Rats
Shared: Action Roguelike · Casual · Roguelite

Noobs Want to Live
Shared: Action Roguelike · Action · Casual

Boneraiser Minions
Shared: Action Roguelike · Roguelite · 2D

Nuclear Throne
Shared: Action Roguelike · Action · Roguelite

Sephiria
Shared: Action Roguelike · Roguelite · Action

暖雪 Warm Snow
Shared: Action Roguelike · Roguelite · 2D

Streets of Rogue
Shared: Action Roguelike · Roguelite · Action

Heroes of Hammerwatch
Shared: Action Roguelike · Roguelite · Action

Seraph's Last Stand
Shared: Action Roguelike · Casual · 2D

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