Games like 三九
Games like 三九 include Paper Bride 3 Unresolved Love, Billionaire Lovers, One Way: The Elevator, Cookie Clicker, and Touhou Mystia's Izakaya. We matched them by the tags players give 三九 on Steam (Casual, Interactive Fiction, Puzzle Platformer, Exploration, and Incremental): closest matches first, and among equally close ones the better-known games.

Paper Bride 3 Unresolved Love
Shared: Puzzle Platformer · Exploration · Interactive Fiction

Billionaire Lovers
Shared: Casual · Interactive Fiction · Anime

One Way: The Elevator
Shared: Casual · Exploration · Incremental

Cookie Clicker
Shared: Casual · Incremental · 2D

Touhou Mystia's Izakaya
Shared: Casual · Anime · 2D

Mirror 2: Project X
Shared: Interactive Fiction · Anime · Casual

To The Core
Shared: Casual · Incremental · 2D

FEZ
Shared: Exploration · Casual · Puzzle Platformer

DAVE THE DIVER
Shared: Casual · Exploration · RPG

Doki Doki Literature Club Plus!
Shared: Anime · Casual · Psychological Horror

Murders on the Yangtze River
Shared: Exploration · Puzzle Platformer · Indie

Zup! X
Shared: Casual · 2D · Puzzle Platformer

Supraland
Shared: Puzzle Platformer · Exploration · First-Person

The Weeping Swan: Ten Days of the City's Fall
Shared: Interactive Fiction · Anime · 2D

One Million Coins
Shared: Casual · Exploration · Incremental

Refunct
Shared: Casual · Puzzle Platformer · First-Person

Road 96: Mile 0
Shared: Interactive Fiction · Exploration · Casual

ANIMAL WELL
Shared: Exploration · Puzzle Platformer · 2D

Vampires' Melody
Shared: Casual · Interactive Fiction · Anime

Mr. Pumpkin 2: Kowloon walled city
Shared: Casual · Exploration · Puzzle Platformer

The Adventure of NAYU
Shared: Casual · Incremental · 2D

Swaying Girl
Shared: Interactive Fiction · Casual · Incremental

Dear Esther: Landmark Edition
Shared: Interactive Fiction · Exploration · First-Person

The Unfinished Swan
Shared: Exploration · Puzzle Platformer · Casual