Games like Cerulean Days
Games like Cerulean Days include ATRI -My Dear Moments-, Parquet, STEINS;GATE, Detroit: Become Human, and Senren * Banka. We matched them by the tags players give Cerulean Days on Steam (Adventure, Visual Novel, Atmospheric, Futuristic, and Story Rich): closest matches first, and among equally close ones the better-known games.

ATRI -My Dear Moments-
Shared: Visual Novel · Story Rich · Anime

Parquet
Shared: Visual Novel · Adventure · Story Rich

STEINS;GATE
Shared: Visual Novel · Story Rich · Anime

Detroit: Become Human
Shared: Story Rich · Futuristic · Adventure

Senren * Banka
Shared: Visual Novel · Adventure · Casual

CLANNAD
Shared: Visual Novel · Story Rich · Anime

GINKA
Shared: Visual Novel · Adventure · Anime

Aokana - Four Rhythms Across the Blue - EXTRA2
Shared: Visual Novel · Story Rich · Romance

Summer Pockets
Shared: Adventure · Visual Novel · Casual

LoveChoice
Shared: Visual Novel · Romance · Story Rich

Aokana - Four Rhythms Across the Blue
Shared: Visual Novel · Adventure · Casual

The Wolf Among Us
Shared: Adventure · Story Rich · Visual Novel

Love, Money, Rock'n'Roll
Shared: Visual Novel · Atmospheric · Anime

ISLAND
Shared: Visual Novel · Adventure · Story Rich

The Hungry Lamb: Traveling in the Late Ming Dynasty
Shared: Visual Novel · Adventure · Story Rich

Higurashi When They Cry Hou - Ch.1 Onikakushi
Shared: Visual Novel · Story Rich · Atmospheric

STEINS;GATE 0
Shared: Visual Novel · Story Rich · Adventure

Florence
Shared: Adventure · Casual · Story Rich

Until Then
Shared: Visual Novel · Story Rich · Adventure

Firewatch
Shared: Adventure · Atmospheric · Story Rich

Zero Escape: The Nonary Games
Shared: Visual Novel · Story Rich · Adventure

eden*
Shared: Visual Novel · Adventure · Story Rich

Danganronpa 2: Goodbye Despair
Shared: Visual Novel · Anime · Story Rich

Fox Hime Zero
Shared: Visual Novel · Adventure · Anime