K-1 Grand Prix is a kickboxing game featuring 32 real K-1 fighters. The game features a 1 player K-1 Kings mode , where the player picks a fighter and faces off against a series of computer controlled fighters, and another mode which is the 2 player K-1 Hercules mode . There is also the K-1 Grand Prix mode which has 16 fighters competing in a tournament to be the K-1 champion.
The story follows the player's journey as they create their own fighter and try to become a K-1 champion. The player gets to choose their fighter's build type, skin color, trunks color, nationality, and gym to train at, which best reflects the fighting style they want. They also get to choose a trainer and 2 sub trainers to help condition them.
Gameplay consists of two opponents in a boxing ring throwing punches and kicks at each other, trying to knock each other to the canvas. The player can practice their moves with a sparring partner in training mode, or observe a match between 2 computer controlled fighters in Ring Side mode.
The gameplay also includes options such as setting the number of rounds, the number of downs, how fast the rounds are, whether to have English or Japanese voice types, and whether to turn vibration on or off. The player can choose to play against opponents with different difficulty levels.