Games like No.9
Games like No.9 include Hook, Zup! S, Hexcells, klocki, and Strange Jigsaws. We matched them by the tags players give No.9 on Steam (Casual, Puzzle, 2D, Indie, and Abstract): closest matches first, and among equally close ones the better-known games.

Hook
Shared: Casual · Puzzle · Abstract

Zup! S
Shared: Casual · Puzzle · 2D

Hexcells
Shared: Casual · Puzzle · Indie

klocki
Shared: Puzzle · Casual · Minimalist

Strange Jigsaws
Shared: Casual · Puzzle · 2D

LYNE
Shared: Puzzle · Casual · Minimalist

Patrick's Parabox
Shared: Puzzle · Abstract · Minimalist

Hexcells Infinite
Shared: Casual · Puzzle · Indie

Baba Is You
Shared: Puzzle · Indie · Logic

Zup!
Shared: Casual · Puzzle · Indie

Zup! F
Shared: Casual · Puzzle · Indie

Zup! 2
Shared: Casual · Puzzle · 2D

Zup! X
Shared: Casual · Puzzle · Indie

Mini Metro
Shared: Puzzle · Minimalist · Casual

Zup! 3
Shared: Casual · Puzzle · Indie

Hexcells Plus
Shared: Puzzle · Casual · Indie

Is This Seat Taken?
Shared: Casual · Puzzle · Logic

Zup! 8
Shared: Casual · Puzzle · Indie

Zup! Z
Shared: Puzzle · Casual · Indie

Zup! 5
Shared: Casual · Puzzle · Indie

Zenge
Shared: Puzzle · Casual · Indie

Hidden Folks
Shared: Casual · Puzzle · Indie

Zup! 6
Shared: Casual · Puzzle · 2D

Mini Motorways
Shared: Casual · Puzzle · Minimalist