Games like Ambitious
Games like Ambitious include Firework, DREDGE, The Room 4: Old Sins, Poppy Playtime, and Outer Wilds. We matched them by the tags players give Ambitious on Steam (Adventure, Lovecraftian, Thriller, Puzzle, and Exploration): closest matches first, and among equally close ones the better-known games.

Firework
Shared: Puzzle · Horror · 2D

DREDGE
Shared: Lovecraftian · Adventure · Exploration

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

Poppy Playtime
Shared: Puzzle · Horror · Adventure

Outer Wilds
Shared: Adventure · Exploration · Puzzle

The Room Three
Shared: Adventure · Puzzle · Lovecraftian

The Room Two
Shared: Puzzle · Adventure · Lovecraftian

Sanfu
Shared: Adventure · Puzzle · 2D

Look Outside
Shared: Lovecraftian · Adventure · Horror

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

Stray
Shared: Adventure · Exploration · Puzzle

Murders on the Yangtze River
Shared: Adventure · Puzzle · Exploration

Rusty Lake Paradise
Shared: Adventure · Puzzle · Horror

ANIMAL WELL
Shared: Puzzle · Exploration · Adventure

Unheard - Voices of Crime
Shared: Thriller · Puzzle · Mystery

The Rewinder
Shared: Adventure · Puzzle · Mystery

Little Nightmares II
Shared: Adventure · Puzzle · Horror

Five Nights at Freddy's: Into the Pit
Shared: Adventure · Exploration · Horror

Firewatch
Shared: Adventure · Exploration · Mystery

The Room
Shared: Puzzle · Adventure · Mystery

OMORI
Shared: Adventure · RPG · Horror

LIMBO
Shared: Puzzle · Adventure · 2D

Moons of Madness
Shared: Adventure · Lovecraftian · Horror

No one lives under the lighthouse Director's cut
Shared: Adventure · Lovecraftian · Horror