You'll want to find the game's 10 Battle Crowns in order to reach the 101% ranking, and also to have more fun in multi-player mode (though not much). In order to win a crown, you must survive battle for 1 minute in an arena. Often, these battles are relatively simple, though a few can frustrate. There are arenas in most areas, and the locations of each crown are detailed below:
Find one arena in front of Snide's Headquarters. In order to enter, you must come as Chunky and lift the huge boulder that is near the hut. Now he can enter and fight for victory and a crown!
The area's second arena is at the entrance to the Fungi Forest stage. Look to the ceiling and you'll notice a mushroom moving around. Shoot it until it changes color. Now use the Kong that is represented by that color (there's a tag barrel in the room). Shoot it until it changes colors again, then change Kongs again. When all five Kongs have participated, a pad appears that will turn Chunky invisible. When he is invisible, he can see a battle arena entrance...
The arena in this stage sits right in front of Funky's Arsenal building.
This arena is under water in a passageway deep in the temple where Tiny was freed, until Lanky shoots a vulture and retrieves a golden banana. Then the water will drain and a Kong can enter the battle arena.
Use the number 2 bananaport to go to the room that leads to the room where Tiny races. Pull the lever there to reveal the entrance to the battle arena. It will appear in the research and development room.
Use Chunky to punch down the gate below Cranky's Lab. That's where the entrance to this stage's battle arena is waiting.
Use teleporter number 5 to reach the wooden walkway in the giant mushroom portion of the level. Once there, drop down through a small hole to find the elusive arena entrance.
There is a log cabin with a bongo drum pad in front of it. Play the bongos and enter as Donkey Kong. You'll be timed in there to play a game, but you can also rotate the room one turn to find the battle arena's entrance.
Lanky must navigate a greenhouse maze in time to win a golden banana. After he grabs the banana, the battle arena pad will appear within the maze.
Fly to the top of the Death Ray machine as Diddy and you'll find the game's last arena. Fairly challenging, but nothing you won't be able to handle.