This is a nice flash remake of the classic Super Mario Bros, with an option to play as Mario or Luigi and take on the evil Koopa and his army, through various levels.
This flash version has most of the features of the original game, so its fun to play. Make your way through each level confronting the evil creatures and reach the flag to proceed to the next level. But hurry up as the time is running out...

Move Left - Left Arrow Key.
Move Right - Right Arrow Key.
Jump - Up Arrow Key.
Crouch - Down Arrow Key.