Refill your fuel
While you're playing any level, hold down the 'TAB' and '2' key on the keyboard and then press the 'F' key. Note: Hold down the '2' key over the 'W' and 'E' keys, not on the numpad.
Unlimited lives
There should be an extra life directly under you once the second level begins. Collect it, then go straight to any monster and let it kill you. Each time you get 1000 points, you get an extra life. Repeat this to build your points and extra lives.
