If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Battle your way through the streets finding new weapons and power ups to rid the underground of the opposing reds. Make sure you visit the dojo before you start your missions so you know what you're doing.
Use arrow keys to move.
Z to punch, throw grenade, set mine.
X to kick, throw grenade.
Hold shift to run.
Space to detonate bomb.
Mouse to aim grenade.