Onion Boy Game

Onion Boy is a retro-style platformer built in the mold of the original Super Mario games. You play a small hero racing through side-scrolling stages to rescue a princess who's been sealed inside a magic bubble by a monster, and every level between you and her is packed with obstacles and enemies standing in the way.

The loop is classic and tight: run, jump, dodge hazards, grab stars and power-ups along the route, and clear out enemies before pushing on to the next stage. A fireball power-up gives you a ranged attack for the tougher stretches, and the run builds toward a boss fight guarding the end.

Controls

• Arrow keys to move, Z to jump, X to throw a fireball, P to pause
• Or WASD to move, K to jump, J to throw a fireball, P to pause
• Touch controls appear automatically on mobile

Tips

• Grab the fireball power-up before a boss stretch — it clears crowded sections far faster than jumping past everything.
• Collect stars along platforms rather than rushing past them; the path to them usually doubles as the safer route.
• Watch an enemy's movement for a beat before committing to a jump past it.

It suits players who grew up on side-scrolling Mario-likes and want a short, familiar run-and-jump session in the browser.