Games like Flux8
Games like Flux8 include LIMBO, Trine 2: Complete Story, Never Alone (Kisima Ingitchuna), Human Fall Flat, and Portal 2. We matched them by the tags players give Flux8 on Steam (Indie, Puzzle, Local Co-Op, Platformer, and Puzzle Platformer): closest matches first, and among equally close ones the better-known games.

LIMBO
Shared: Indie · Puzzle · Puzzle Platformer

Trine 2: Complete Story
Shared: Platformer · Puzzle Platformer · Puzzle

Never Alone (Kisima Ingitchuna)
Shared: Indie · Local Co-Op · Platformer

Human Fall Flat
Shared: Puzzle · Physics · Puzzle Platformer

Portal 2
Shared: Puzzle · Platformer · Puzzle Platformer

ibb & obb
Shared: Puzzle · Local Co-Op · Indie

CATO: Buttered Cat
Shared: Puzzle · Puzzle Platformer · Indie

FEZ
Shared: Puzzle · Indie · Platformer

Defy Gravity Extended
Shared: Indie · Puzzle · Platformer

Webbed
Shared: Cute · Puzzle Platformer · Physics

PICO PARK
Shared: Local Co-Op · Puzzle Platformer · Platformer

INSIDE
Shared: Puzzle Platformer · Indie · 2.5D

Pikuniku
Shared: Indie · Puzzle · Cute

Trine 4: The Nightmare Prince
Shared: Local Co-Op · Puzzle Platformer · 2.5D

Portal
Shared: Puzzle · Puzzle Platformer · Physics

Toki Tori
Shared: Indie · Puzzle · Platformer

The Pedestrian
Shared: Puzzle · Puzzle Platformer · Platformer

Braid
Shared: Puzzle · Indie · Puzzle Platformer

Seen
Shared: Indie · Puzzle · Platformer

The Cave
Shared: Puzzle · Platformer · Local Co-Op

Zup!
Shared: Puzzle · Indie · Physics

Little Nightmares
Shared: Puzzle · Indie · Puzzle Platformer

BattleBlock Theater®
Shared: Platformer · Level Editor · Local Co-Op

Trine Enchanted Edition
Shared: Puzzle Platformer · Local Co-Op · Physics