Super Mario Bros

Controls:
Up = Jump
Right/Left = Right/Left
Down = Go Down Pipe
Space = Shoot(if enabled)

World0 => Koopas, Piranha Plant, and Fire Flower item
World1 => Fire World
World2 => Underground (hard) (tip: you don't need to jump on the blue crystal to make it to the 1st platform.
Also, blue beetles might re-spawn close to you if you kill them.)
World3 => Underwater swimming
World4 => Boss => Bowser (really hard) (tip: don't jump on his head for too long at a time or he'll hit you)

Note: Seems to only work on firefox as of recently.

Developed by: Ashvinder Grewal & Uriel Sade