Games like The Floor Above
Games like The Floor Above include No, I'm not a Human, The Test, The Casting of Frank Stone™, That's not my Neighbor, and Little Nightmares II. We matched them by the tags players give The Floor Above on Steam (Simulation, Casual, Adventure, Horror, and Psychological Horror): closest matches first, and among equally close ones the better-known games.

No, I'm not a Human
Shared: Horror · Psychological Horror · Singleplayer

The Test
Shared: Simulation · Multiple Endings · Psychological Horror

The Casting of Frank Stone™
Shared: Horror · Adventure · Multiple Endings

That's not my Neighbor
Shared: Casual · Adventure · Simulation

Little Nightmares II
Shared: Adventure · Horror · Singleplayer

The Test: Hypothesis Rising
Shared: Simulation · Horror · Multiple Endings

Poppy Playtime
Shared: Horror · Singleplayer · Psychological Horror

Darkwood
Shared: Horror · Adventure · Psychological Horror

Death and Taxes
Shared: Simulation · Psychological Horror · Choices Matter

Sally Face - Episode One
Shared: Psychological Horror · Horror · Adventure

SOMA
Shared: Horror · Psychological Horror · Story Rich

DAVE THE DIVER
Shared: Casual · Adventure · Singleplayer

Little Nightmares
Shared: Horror · Adventure · Singleplayer

Tiny Bunny
Shared: Horror · Psychological Horror · Story Rich

The Coffin of Andy and Leyley
Shared: Psychological Horror · Multiple Endings · Story Rich

SILENT HILL 2
Shared: Horror · Psychological Horror · Story Rich

MiSide
Shared: Psychological Horror · Horror · Singleplayer

[Chillas Art] The Convenience Store
Shared: Horror · Simulation · Adventure

Slay the Princess — The Pristine Cut
Shared: Psychological Horror · Horror · Choices Matter

Little Misfortune
Shared: Psychological Horror · Adventure · Horror

Detroit: Become Human
Shared: Choices Matter · Multiple Endings · Singleplayer

Emily is Away <3
Shared: Simulation · Casual · Choices Matter

Layers of Fear (2016)
Shared: Horror · Psychological Horror · Singleplayer

Fran Bow
Shared: Psychological Horror · Horror · Adventure