Games like MoonSpire
Games like MoonSpire include FEZ, Papers, Please, Celeste, Baba Is You, and SANABI. We matched them by the tags players give MoonSpire on Steam (Casual, Singleplayer, Puzzle, 2D Platformer, and Pixel Graphics): closest matches first, and among equally close ones the better-known games.

FEZ
Shared: Puzzle · Pixel Graphics · Singleplayer

Papers, Please
Shared: Singleplayer · Pixel Graphics · Indie

Celeste
Shared: Pixel Graphics · 2D Platformer · Singleplayer

Baba Is You
Shared: Puzzle · Singleplayer · Pixel Graphics

SANABI
Shared: Pixel Graphics · 2D Platformer · Singleplayer

Super Meat Boy
Shared: 2D Platformer · Singleplayer · Pixel Graphics

There Is No Game: Wrong Dimension
Shared: Puzzle · Casual · Pixel Graphics

Braid
Shared: Puzzle · 2D Platformer · Singleplayer

Pizza Tower
Shared: 2D Platformer · Singleplayer · Pixel Graphics

Vampire Survivors
Shared: Pixel Graphics · Singleplayer · Casual

Unpacking
Shared: Casual · Pixel Graphics · Puzzle

Zup! S
Shared: Casual · Puzzle · Singleplayer

Please, Don’t Touch Anything
Shared: Puzzle · Singleplayer · Pixel Graphics

VVVVVV
Shared: Pixel Graphics · 2D Platformer · Singleplayer

Out There Somewhere
Shared: Puzzle · Pixel Graphics · Indie

OneShot
Shared: Pixel Graphics · Puzzle · Singleplayer

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Singleplayer · Retro

ElecHead
Shared: Puzzle · Pixel Graphics · Singleplayer

Katana ZERO
Shared: Pixel Graphics · 2D Platformer · Indie

The Messenger
Shared: Pixel Graphics · Retro · Singleplayer

Gunpoint
Shared: Puzzle · Singleplayer · Pixel Graphics

Gorogoa
Shared: Puzzle · Singleplayer · Casual

Defy Gravity Extended
Shared: Puzzle · Singleplayer · Casual

Sonic Origins
Shared: 2D Platformer · Casual · Pixel Graphics