Games like Terra's Aquarium
Games like Terra's Aquarium include Sally Face - Episode One, Firework, SOMA, Nine Sols, and Hellblade: Senua's Sacrifice. We matched them by the tags players give Terra's Aquarium on Steam (Action, 2D, Hand-drawn, Atmospheric, and Dark): closest matches first, and among equally close ones the better-known games.

Sally Face - Episode One
Shared: Dark · Horror · Story Rich

Firework
Shared: 2D · Horror · Atmospheric

SOMA
Shared: Atmospheric · Horror · Dark

Nine Sols
Shared: 2D · Action · Hand-drawn

Hellblade: Senua's Sacrifice
Shared: Atmospheric · Dark · Story Rich

Hollow Knight
Shared: 2D · Atmospheric · Indie

BioShock™ Remastered
Shared: Atmospheric · Action · Horror

Dead Space (2008)
Shared: Action · Horror · Sci-fi

INSIDE
Shared: Atmospheric · Dark · Horror

BioShock™
Shared: Action · Atmospheric · Horror

Little Nightmares
Shared: Atmospheric · Horror · Dark

LIMBO
Shared: 2D · Dark · Atmospheric

Alan Wake
Shared: Action · Horror · Atmospheric

Tiny Bunny
Shared: Atmospheric · Horror · Dark

Black Mesa
Shared: Action · Atmospheric · Sci-fi

Half-Life 2
Shared: Action · Sci-fi · Atmospheric

Poppy Playtime
Shared: Horror · Dark · Singleplayer

Resident Evil 4
Shared: Action · Horror · Dark

DISTRAINT: Deluxe Edition
Shared: 2D · Horror · Indie

No, I'm not a Human
Shared: Horror · Atmospheric · Indie

Bendy and the Ink Machine
Shared: Horror · Dark · Singleplayer

BioShock™ 2 Remastered
Shared: Action · Atmospheric · Horror

METRO Last Light Redux
Shared: Action · Atmospheric · Horror

Little Nightmares II
Shared: Horror · Dark · Atmospheric