Games like Arthur's Sand Castle Contest
Games like Arthur's Sand Castle Contest include Scribblenauts Unlimited, Storyteller, There Is No Game: Wrong Dimension, Return to Monkey Island, and Machinarium. We matched them by the tags players give Arthur's Sand Castle Contest on Steam (Adventure, Casual, Education, Point & Click, and Sandbox): closest matches first, and among equally close ones the better-known games.

Scribblenauts Unlimited
Shared: Casual · Adventure · Puzzle

Storyteller
Shared: Point & Click · Adventure · Puzzle

There Is No Game: Wrong Dimension
Shared: Adventure · Point & Click · Puzzle

Return to Monkey Island
Shared: Adventure · Point & Click · Puzzle

Machinarium
Shared: Point & Click · Puzzle · Adventure

Terraria
Shared: Sandbox · Adventure · 2D

Pajama Sam: No Need to Hide When It's Dark Outside
Shared: Adventure · Point & Click · Casual

House Flipper
Shared: Casual · Sandbox · Building

Old Man's Journey
Shared: Adventure · Casual · Puzzle

Strange Jigsaws
Shared: Adventure · Casual · Puzzle

The Room
Shared: Point & Click · Adventure · Puzzle

Lost in Play
Shared: Point & Click · Puzzle · 2D

Gorogoa
Shared: Puzzle · Casual · Point & Click

Garry's Mod
Shared: Sandbox · Casual · Building

Lil' Guardsman
Shared: Adventure · Casual · Point & Click

Gomo
Shared: Adventure · Point & Click · Casual

Neighbours back From Hell
Shared: Point & Click · Adventure · Puzzle

Morphopolis
Shared: Casual · Adventure · Puzzle

Scribblenauts Unmasked: A DC Comics Adventure
Shared: Adventure · Casual · Sandbox

Poly Bridge
Shared: Puzzle · Sandbox · Building

Moncage
Shared: Casual · Adventure · Puzzle

Samorost 1
Shared: Casual · Point & Click · Puzzle

Deponia
Shared: Adventure · Point & Click · Puzzle

12 Labours of Hercules
Shared: Casual · Adventure · Puzzle