Your fiancee, kidnapped by slave traders, is being held prisoner on the top floor of a shanty in Shanghai. You are (guess where?) at the bottom of a shanty in Shanghai, and your task is to rescue her. Actually, it looks more like a hi-tech warehouse than a shanty, with a very familiar set of girders and ladders between you and your beloved. There are also a few slow-moving nasties - pink ones and blue ones - strolling around, and a sword, a key and a stick of dynamite to help you on your way.
If you light the dynamite at a brazier and drop it anywhere, it will blast away anything that happens to be on that floor when the fuse burns down. Otherwise, it's the usual trek to the top, use the key to open the door, invite your betrothed to follow you downstairs to live happily ever after. The guardian who was looking after her, an ugly geezer with flashing eyes, will soon traipse after you but it's not too difficult to evade him.
Shanghai's graphics are predictable but pleasant enough and the animation smooth but unexciting. The sound is feeble - just the odd bleep when you stumble into somebody or something and an irritating alarm clock when you run out of time.
The most frustrating thing of all is the behaviour of your fiancee, a fearsome creature with red hair and a blue face. You'd think she'd be grateful for your heroic rescue and follow you diligently to safety. But if you go too far ahead, she loses interest and wanders round aimlessly, and if you happen to bump into her she destroys you. Makes you wonder why you bothered!