Once upon a time there was a young man named Jack who had a beautiful girlfriend called Jill - until the local giant incarcerated her in his castle. Being a brave sort of chap, Jack decided to enter the castle to attempt a rescue.
The castle takes the form a 45-screen maze which you must negotiate in order to find the key which will unlock Jill's dungeon. Different areas are sealed off by coloured doors. These are unlocked by coloured keys which are to be found around the castle.
I don't know if the giant is a greengrocer in his spare time but the castle is littered with fruit. Every one must be collected before you are allowed to free Jill.
As soon as you have released your beloved, the giant will awaken. You must therefore escape from the castle within the next two minutes. The 45 screens do not need to be completed in sequence, and you are free to wander from place to place as you seek the next key.
Each screen is big, colourful and normally patrolled by a nicely detailed bad guy. There are also secret passages which can take you from one section to another without the need for a key.
I found Jack Attack a well written, fun to play and sensibly priced program.