Press space, and read the instructions. Running it on turbo mode may help, depending on the computer and webcam configurations, but in others, it will turn the game itself faster, but will slow down the video from the webcam, making the gameplay worse.
Notes: 1: I didn't test the game after the last changes i made, because i don't have a computer with webcam now, but i think it will work just fine. Please report any bug on the game. 2: The game works by measuring the "amount of movement" of the image from the webcam, so you must be the only thing moving on the image. 3: The image noise may cause problems. Play it on well lit place to avoid noise, but if the noise is still causing problems (such as the enemy being hit without touching him), there is a variable to filter noise, in the Stage script, this variable is the first to be set. The maximal value is 100. 3: The use of webcam on scratch turn the game extremely heavy. Even a i5 processor with 4Gb of memory, running this game on turbo mode and the flash plugin with maximal priority, the game was still a little slow, but still functional. Sometimes, moving slower helps, because if you move too fast, it may not recognize the movement. Credits: I took the sprite images from: http://www.mortalkombatwarehouse.com/ The sounds from: http://soundfxcenter.com/ And edited the images with GIMP: http://www.gimp.org/