Games like Defunct
Games like Defunct include Haste, Sonic Adventure DX, Pizza Tower, GRIS, and Sonic Lost World. We matched them by the tags players give Defunct on Steam (Adventure, Racing, Indie, Fast-Paced, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Haste
Shared: Fast-Paced · Racing · Adventure

Sonic Adventure DX
Shared: Adventure · Platformer · Singleplayer

Pizza Tower
Shared: Indie · Fast-Paced · Great Soundtrack

GRIS
Shared: Indie · Adventure · Singleplayer

Sonic Lost World
Shared: Adventure · Platformer · Singleplayer

Sonic Adventure 2
Shared: Adventure · Fast-Paced · Platformer

Sonic Mania
Shared: Platformer · Adventure · Fast-Paced

Hollow Knight
Shared: Platformer · Indie · Singleplayer

SONIC X SHADOW GENERATIONS
Shared: Fast-Paced · Adventure · Singleplayer

BEEP
Shared: Adventure · Indie · Platformer

Super Hexagon
Shared: Indie · Fast-Paced · Singleplayer

Drift86
Shared: Racing · Indie · Casual

Hollow Knight: Silksong
Shared: Indie · Singleplayer · Adventure

Kao the Kangaroo: Round 2 (2003 re-release)
Shared: Adventure · Racing · Casual

Slime Rancher
Shared: Adventure · Singleplayer · Colorful

A Story About My Uncle
Shared: Adventure · Indie · Singleplayer

SpeedRunners
Shared: Racing · Indie · Fast-Paced

ABZU
Shared: Adventure · Singleplayer · Indie

Castle of Illusion
Shared: Adventure · Platformer · Casual

Sonic Forces
Shared: Adventure · Fast-Paced · Singleplayer

Yooka-Laylee
Shared: Adventure · Indie · Platformer

FEZ
Shared: Indie · Platformer · Adventure

A Hat in Time
Shared: Adventure · Indie · Great Soundtrack

Geometry Dash
Shared: Singleplayer · Great Soundtrack · Platformer