1. Be sure the CAPS LOCK (ASCII/DIN) key is not pressed before loading the game!  (Really weird, huh?)
2. Insert the disk and just type RUN"*" (or press Shift + Run/Stop) ... might need to change if not disk unit 8...
3. After the game loads, press F1, F3, or F5 to give yourself some credit(s)
4. Once you have credit(s), press 1 or 2 (above the Q,W keys) to start a 1 or 2 player game
5. In the game you can use:

• Keyboard - Cursor Keys (at top) or numeric keypad (2=down, 6=right, 8=up, 4=left) and Shift to fire
• Joystick in game port 2
• Mouse in game port 1

In any case, press the SpaceBar to use your ZAP ability (once per level).