In Kirby: Nightmare in Dream Land you have the ability to hook up with other friends and play together. The two things you'll be able to do are play Sub Games and Adventure Mode. If you want to play the Sub Games with your friends, only you need to have the actual game cartridge. If you want to play together in Adventure Mode, you'll all need to have the game. To connect you'll need the Nintendo Gameboy Advance Link Cable.
There are a few special rules for Adventure Mode.
- You will begin on the highest level everyone has completed.
- All players will enter the first door one player entered.
- Nobody can enter a new doorway unless everyone is grouped around it.