Successfully complete the game after finding all 300 monkeys. Highlight "New Game" at the main menu, then press L1 + Start to play as Spike from the original Ape Escape.
Successfully complete the Ninja Hideout level to unlock the Dance Monkey Dance mini-game.
Defeat Specter to unlock the Monkey Climber mini-game to unlock the Monkey Climber mini-game.
Successfully complete the Enter The Monkey level to unlock the Monkey Soccer mini-game.
Get all 300 monkeys to face the real final Boss. Win the battle to view the good ending.
At the menu screen, hold R1 and rotate the Left Analog-stick and Right Analog-stick to control Zapper's facial expressions.
Hold X while the credits are displayed.
In the Ninja Hideout level, there is a garden of bamboo plants. Also nearby are a couple of rocks. If you break the rocks with your stick, there will be some cookies and a jacket. You can keep going to another part of the level and returning. The cookies and life will be there again. Do this as many times as needed to get 99 lives. Note: The fastest way to do this is to wear your Super Hoop to move faster.
Go to the casino level. It helps to get rid of any black pants wearing monkeys in the first part of the level. Break open all of the slot machines in a counter-clockwise direction. After awhile you will meet a rat-looking enemy that takes your money when you run into it. Let him hit you and allow him to take your gold. Then, quickly hit him and all of your gold will be dropped. Grab all of it quickly; after you collect 5 gold pieces they turn to silver stars. After 5 silver stars, they turn into gold stars which are worth 10 gold pieces. Continue hitting the slots and you will find one more of these rats. Additionally, after you defeat Spector (Mech-Monkey Sub-Boss) and unlock the extra monkeys, go to the Simian Citadel level. Toward the end of this level, you will find a wizard-monkey named Tommy. If you do not catch him, he constantly creates enemies. One of these enemies is the rat thief. Let him steal your coins, then steal them back. You can use the Super Hoop to catch him. Keep repeating this until your coins are at 999. Note: even if you catch Tommy and save the game, you can still return in time trial mode to perform this trick.
Go to Casino City level and destroy the slot machines going left and around in a circle. Once all the slot machines are destroyed, leave the room and return. Destroy all the slot machines again and repeat if desired. Note: You may want do this after you catch all the monkeys in the level so that the monkeys with black pants and guns do not hurt you.
After getting all 300 monkeys, enable the "Play as Spike" code. While playing as Spike, even though you have all the gadgets you do not have the See-All Scope which lets you find the monkeys you get with the Magic Punch gadget.
Go to the soundtracks area in the extras menu. Select either "Gotcha Rythmn" or "Monkeys Gonna Getchu". Listen to them to hear that they are switched.