Games like Project Oasis
Games like Project Oasis include OneShot, Undertale, Unpacking, Changed, and The Last Campfire. We matched them by the tags players give Project Oasis on Steam (Roguelite, Puzzle, Cute, RPG, and Story Rich): closest matches first, and among equally close ones the better-known games.

OneShot
Shared: Story Rich · Cute · Puzzle

Undertale
Shared: Story Rich · Multiple Endings · RPG

Unpacking
Shared: Cute · Puzzle · Pixel Graphics

Changed
Shared: Cute · Puzzle · Pixel Graphics

The Last Campfire
Shared: Puzzle · Cute · Adventure

To the Moon
Shared: Story Rich · Pixel Graphics · RPG

DAVE THE DIVER
Shared: Pixel Graphics · Adventure · RPG

Outcore: Desktop Adventure
Shared: Story Rich · Puzzle · Cute

Rakuen
Shared: Puzzle · Story Rich · Cute

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Story Rich · Adventure

Papers, Please
Shared: Puzzle · Pixel Graphics · Multiple Endings

OMORI
Shared: Story Rich · RPG · Pixel Graphics

There Is No Game: Wrong Dimension
Shared: Puzzle · Pixel Graphics · Adventure

Little Witch in the Woods
Shared: Cute · Puzzle · Pixel Graphics

Tales of the Black Forest
Shared: RPG · Pixel Graphics · Story Rich

The Talos Principle
Shared: Puzzle · Story Rich · Philosophical

Eastward
Shared: Story Rich · Pixel Graphics · RPG

DRAPLINE
Shared: Roguelite · RPG · Multiple Endings

Carto
Shared: Puzzle · Cute · Story Rich

Otaku's Adventure
Shared: Multiple Endings · RPG · Puzzle

CrossCode
Shared: RPG · Puzzle · Pixel Graphics

Back to the Dawn
Shared: RPG · Story Rich · Pixel Graphics

Finding Paradise
Shared: Story Rich · RPG · Pixel Graphics

Ib
Shared: Story Rich · Pixel Graphics · Puzzle