It starts out as a golf game, but when you put the ball in the hole, a Gorilla appears and drags you off the a hidden doorway to another dimension and leaves you in a dungeon, you must then escape from the dungeon and make your way back to the golf course to get to the next hole.
Every time you get the ball in a hole you are kidnapped by the Gorilla and dragged to a different dungeon in a different world. On the final 18th hole you give the Gorilla a hand held games console and he loses interest in the magic portal key. A device that reveals portals to other dimensions and opens them. You are then free to play uninterrupted golf or interdimentional dungeon quests, whatever floats your boat. That is what you unlock at the end of the game.
The hardest part of the game would be explaining to your mum or person that enters your room that you are playing a golf game. Where would you even start?
The portal hopping Gorilla is called Handy and he is a bit like Donkey Kong but he throws his own poop at you instead of Barrels. The poop gives you concussion and that allows him to kidnap you if you try to run from him.