Games like Once Again
Games like Once Again include Florence, GRIS, OPUS: Echo of Starsong - Full Bloom Edition, Before Your Eyes, and To the Moon. We matched them by the tags players give Once Again on Steam (Indie, Adventure, Casual, Colorful, and Female Protagonist): closest matches first, and among equally close ones the better-known games.

Florence
Shared: Indie · Adventure · Casual

GRIS
Shared: Indie · Adventure · Female Protagonist

OPUS: Echo of Starsong - Full Bloom Edition
Shared: Visual Novel · Indie · Female Protagonist

Before Your Eyes
Shared: Indie · Emotional · Story Rich

To the Moon
Shared: Indie · Adventure · Story Rich

OPUS: Rocket of Whispers
Shared: Indie · Visual Novel · Adventure

Mirror 2: Project X
Shared: Female Protagonist · Visual Novel · Casual

Carto
Shared: Indie · Adventure · Female Protagonist

Assemble with Care
Shared: Indie · Casual · Female Protagonist

If Found...
Shared: Indie · Casual · Adventure

Brothers - A Tale of Two Sons
Shared: Adventure · Indie · Story Rich

Beacon Pines
Shared: Visual Novel · Colorful · Story Rich

Call of the Sea
Shared: Adventure · Indie · Story Rich

The Cosmic Wheel Sisterhood
Shared: Female Protagonist · Visual Novel · Adventure

Far Away
Shared: Visual Novel · Female Protagonist · Singleplayer

Chants of Sennaar
Shared: Adventure · Indie · Colorful

Old Man's Journey
Shared: Adventure · Indie · Casual

Mixtape
Shared: Adventure · Singleplayer · Casual

There Is No Game: Wrong Dimension
Shared: Indie · Adventure · Casual

Gorogoa
Shared: Indie · Casual · Singleplayer

Neva
Shared: Adventure · Indie · Female Protagonist

Sanfu
Shared: Adventure · Colorful · Visual Novel

Until Then
Shared: Visual Novel · Emotional · Story Rich

The Last Campfire
Shared: Adventure · Indie · Singleplayer