If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Megaman 3 is a platform and action game. The player controls Mega Man as he traverses eight stages to defeat the bosses, Dr. Wily's Robot Masters: Magnet Man, Hard Man, Top Man, Shadow Man, Spark Man, Snake Man, Gemini Man, and Needle Man.
Arrow keys to move.
Z - Shoot.
X - Jump.