Games like Scylla's Depths
Games like Scylla's Depths include Barotrauma, Resident Evil 4, Resident Evil 7 Biohazard, Resident Evil Village, and Dead Space. We matched them by the tags players give Scylla's Depths on Steam (Action, 2D, Underwater, Simulation, and Survival Horror): closest matches first, and among equally close ones the better-known games.

Barotrauma
Shared: 2D · Survival Horror · Underwater

Resident Evil 4
Shared: Action · Survival Horror · Horror

Resident Evil 7 Biohazard
Shared: Survival Horror · Horror · Singleplayer

Resident Evil Village
Shared: Action · Survival Horror · Horror

Dead Space
Shared: Survival Horror · Horror · Singleplayer

Outlast
Shared: Survival Horror · Horror · Singleplayer

Subnautica 2
Shared: Underwater · Horror · Survival

The Forest
Shared: Horror · Survival · Action

Resident Evil 2
Shared: Survival Horror · Action · Singleplayer

Feed and Grow: Fish
Shared: Underwater · Simulation · Action

Outlast 2
Shared: Survival Horror · Horror · Singleplayer

Dead by Daylight
Shared: Survival Horror · Horror · Survival

Resident Evil Requiem
Shared: Action · Survival Horror · Horror

Darkwood
Shared: Action · Survival Horror · Horror

Subnautica
Shared: Underwater · Horror · Survival

Alien: Isolation
Shared: Survival Horror · Horror · Action

Resident Evil 4 (2005)
Shared: Action · Survival Horror · Horror

Halloween: The Game
Shared: Horror · Singleplayer · Survival Horror

Five Nights at Freddy's
Shared: Survival Horror · Singleplayer · Horror

Poppy Playtime
Shared: Singleplayer · Horror · Survival Horror

The Evil Within 2
Shared: Survival Horror · Action · Horror

Subnautica: Below Zero
Shared: Underwater · Singleplayer · Survival

Resident Evil 3
Shared: Action · Horror · Survival Horror

Dead Space™ 2
Shared: Survival Horror · Action · Horror