Games like Billy 101
Games like Billy 101 include SANABI, Webbed, Sonic Origins, Celeste, and MO:Astray. We matched them by the tags players give Billy 101 on Steam (Adventure, Action, 2D Platformer, Robots, and Colorful): closest matches first, and among equally close ones the better-known games.

SANABI
Shared: Action · Adventure · Pixel Graphics

Webbed
Shared: 2D Platformer · Pixel Graphics · Cute

Sonic Origins
Shared: Action · Adventure · 2D Platformer

Celeste
Shared: Pixel Graphics · 2D Platformer · Adventure

MO:Astray
Shared: Action · Adventure · Pixel Graphics

PRAGMATA
Shared: Action · Adventure · Cute

Planet of Lana
Shared: Action · 2D Platformer · Puzzle Platformer

Broforce
Shared: Action · Pixel Graphics · Side Scroller

Sonic Mania
Shared: Adventure · Pixel Graphics · Action

Out There Somewhere
Shared: Adventure · Pixel Graphics · Action

ElecHead
Shared: Action · Puzzle Platformer · Adventure

Lone Fungus
Shared: Adventure · 2D Platformer · Action

Momodora: Reverie Under The Moonlight
Shared: 2D Platformer · Pixel Graphics · Side Scroller

Gato Roboto
Shared: Action · Adventure · Pixel Graphics

Haiku, the Robot
Shared: Adventure · Robots · Pixel Graphics

Super Bernie World
Shared: Action · Adventure · 2D Platformer

Gravity Circuit
Shared: Action · Pixel Graphics · 2D Platformer

Mind Over Magnet
Shared: Adventure · Robots · 2D Platformer

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Adventure · Action

Iconoclasts
Shared: Action · Adventure · Pixel Graphics

Stray
Shared: Adventure · Robots · Cute

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

UFO 50
Shared: Action · Pixel Graphics · Adventure

Pikuniku
Shared: Adventure · Action · Cute