Pretty good
While the graphics were nice, the music and sound effects were lackluster. They really didn't put much emotion into the flash. The controls were easy, but it felt clunky because you can't press multiple buttons at once. Punching and kicking in a 2D sidescroller is pretty early 90's. It doesn't have much appeal nowadays. Also, the jumping is pretty stiff.
A few flaws, but otherwise this is a good game.