Games like Marble Skies
Games like Marble Skies include Kao the Kangaroo: Round 2 (2003 re-release), Retrowave, Chained Together, BEEP, and Drift86. We matched them by the tags players give Marble Skies on Steam (Indie, Casual, Racing, Action, and 3D Platformer): closest matches first, and among equally close ones the better-known games.

Kao the Kangaroo: Round 2 (2003 re-release)
Shared: Casual · Action · 3D Platformer

Retrowave
Shared: Indie · Racing · Casual

Chained Together
Shared: Casual · Adventure · Platformer

BEEP
Shared: Indie · Adventure · Platformer

Drift86
Shared: Racing · Casual · Indie

Sonic Adventure 2
Shared: Action · 3D Platformer · Adventure

Sonic Adventure DX
Shared: 3D Platformer · Platformer · Adventure

Pumpkin Jack
Shared: Action · Indie · Adventure

UFO 50
Shared: Indie · Action · Strategy

Haste
Shared: 3D Platformer · Action · Racing

Need for Speed™ Unbound
Shared: Racing · Action · Casual

Caster
Shared: Indie · Action · Casual

Pikuniku
Shared: Indie · Casual · Adventure

ALTF4
Shared: 3D Platformer · Action · Casual

Yooka-Laylee
Shared: Indie · 3D Platformer · Adventure

SpeedRunners
Shared: Racing · Indie · Action

Need for Speed™ Heat
Shared: Racing · Action · Adventure

Tiny and Big: Grandpas Leftovers
Shared: Indie · 3D Platformer · Platformer

Rock 'N' Roll Defense
Shared: Casual · Action · Indie

Clustertruck
Shared: Action · 3D Platformer · Indie

Sparkle 2 Evo
Shared: Indie · Casual · Action

Hollow Knight
Shared: Indie · Platformer · Adventure

Dust: An Elysian Tail
Shared: Indie · Action · Platformer

Rogue Legacy 2
Shared: Indie · Action · Arcade