This has all the ingredients of an addictive arcade game - good graphics, fast action and plenty of bonuses.
The first screen shows a pattern of squares. You must visit each of them twice to change their colour. When all have been turned to the second colour you progress onto the next screen where squares are arranged in a more difficult configuration, and so on.
On all screens there are black skulls, making good timing imperative if you are to avoid them. Points are deducted should you hesitate, and a life lost if caught.
On every screen there's a letter square containing one letter from the word Extra. When you've managed to reach and cross all five letters, a bonus life is awarded. Ringing the bell will boost your score, but this may only be done once. The letter square also changes into a bonus square to increase your score even more.
Definitely one of those games that become more addictive the more you play. To begin with it all seems very easy, but by the time you've entered the fourth screen, fingers are clenched. Needs Extended Basic and joystick.