If a permission dialog appears, Click Yes.
Then click the game so that it will have keyboard focus

If the sound is too choppy follow these steps:
1. open up the task manager (by pressing CTLR+ALT+DEL)
2. go to the processes tab
3. right click java.exe and set the priority to Above Normal

Keys:
Up = Jump
Down = Duck
Left = Walk Left
Right = Walk Right
z = Punch
x = Kick

Enter = Select
Escape = Back/Quit