Games like Lily
Games like Lily include Poppy Playtime, Outer Wilds, Firewatch, What Remains of Edith Finch, and MiSide. We matched them by the tags players give Lily on Steam (Adventure, First-Person, Puzzle, Mystery, and Thriller): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Puzzle · First-Person · Singleplayer

Outer Wilds
Shared: Adventure · Mystery · Exploration

Firewatch
Shared: Adventure · First-Person · Mystery

What Remains of Edith Finch
Shared: First-Person · Mystery · Adventure

MiSide
Shared: Psychological Horror · First-Person · Singleplayer

Blue Prince
Shared: Puzzle · Mystery · Exploration

Inside the Backrooms
Shared: Puzzle · Adventure · Psychological Horror

The Room 4: Old Sins
Shared: Puzzle · Adventure · Mystery

Garten of Banban
Shared: First-Person · Puzzle · Psychological Horror

Escape the Backrooms
Shared: First-Person · Psychological Horror · Adventure

The Room Two
Shared: Puzzle · Mystery · Adventure

The Room
Shared: Puzzle · Mystery · Adventure

Subliminal
Shared: Psychological Horror · Mystery · First-Person

Firework
Shared: Puzzle · Mystery · Indie

Superliminal
Shared: First-Person · Puzzle · Thriller

The Witness
Shared: Puzzle · First-Person · Exploration

The Room Three
Shared: Adventure · Puzzle · Mystery

Bendy and the Ink Machine
Shared: First-Person · Puzzle · Singleplayer

INFRA
Shared: Puzzle · First-Person · Adventure

Dread Flats
Shared: Adventure · Mystery · Psychological Horror

Layers of Fear (2016)
Shared: First-Person · Psychological Horror · Adventure

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

Five Nights at Freddy's: Security Breach
Shared: First-Person · Adventure · Singleplayer

The Exit 8
Shared: Puzzle · Exploration · First-Person