Unlock Ex-Agunimon:

To unlock Ex-Agunimon-Complete the game with all six characters. Then using either Agunimon, Kazemon or Kumamon complete the game with 800 points.(I recomend you put easy difficulty and 3 minutes(180 seconds). To unlock Ex-Lobomon, do the same stated above, but use either Lobomon, Beetlemon or Loweemon. To unlock Loweemon-What I did was complete the game with Lobomon and Agunimon.
Sent in by: Daryus

Ex Angimon  -  To unlock Ex Angimon, just clear the game with all six characters or beat 5 or more people in VS. mode

Digimon Shoot mini-game:  Successfully complete the game to unlock the Digimon Shoot mini-game.

Chaos-Lobomon and Chaos-Agunimon:  To get Chaos-Lobomon and Chaos-Agunimon, you must complete the game with all six players (including Loweemon), any number of spirits (blue balls), and any difficulty setting. Then, complete the game with Agunimon and Lobomon (recommended) and get 800 or more spirits (3 minute games) After you complete the game with Agunimon and get 800 spirits, an egg will appear with Ex-Agunimon in it. Ex-Agunimon is another shade of red (and can be black), and his new attack is Down + B (repeatedly) is Pyro-Darts. He can also slide EVO to Emperor Greymon (very strong). After you complete the game with Lobomon or Loweemon and get 800 spirits, an egg will appear with Ex-Lobomon. He is light blue and can be green. His new attack (Up + B) is Jumping Kick and Sword Slash. This attack is tricky and you need to know when to hit it. A good time is in the air. If you do it to close to your opponent, you will jump over him. He can also transform into Magna Garurumon. Both of their Ancient EVO is the same. It is the Digimon that destroyed Lucemon in the show. He shoots a beam of blue and red which hurts his enemies very badly.

Loweemon:  Loweemon is Koegy (dark spirit). To get Loweemon, you must complete single player mode with Lobomon (light spirit) with any amount of D-power. After the congratulations screen, you will see a message about getting a new Digimon. Note: Loweemon can also super attack.

Successfully complete game in normal mode with any character. After the ending credits, Loweemon will appear from a yellow Digi-Egg.

Flying Burninggraymon:  When you are Agunimon (fire spirit) and are able to slide evolution to Burninggraymon, jump and press Up + B. Burninggraymon will fly across the screen. Note: If Burninggraymon hits your enemy, it will make a lot of D-Spirit balls fall out, and occasionally some ancient spirits

Defeating Kerpymon:  Keep firing your weapon/spirit shot at his head and repeat as necessary. When the cloud appears, attack it before it zaps you. Then, repeat attacking but avoid his attacks. When he uses his Black Hole attack, use your Speed Run and go to the corner of the screen before he gets you.

If you are Beetlemon, try to hover when Kerpymon's Storm Of Judgment Cloud strikes. The moment that the cloud appears on the field and Kerpymon disappears, strike it with your mid-air kick. This should cause it to disappear. It is wise to stand on the top left platform (the right may also work) and wait for a moment to strike. The Down + B move should manage to strike Kerpymon, and possibly block the gray/white balls that it shoots. When you are in beast mode, use the mid-air Bolo Thunder (Up + B in air) attack above Kerpymon more often, then the Electron Cannon Attack (Down + B). For the other characters, stick to long-range attacks. Use two mid-air long range attacks on the Storm Cloud. With Chaos-Lobomon, use your normal Lobo-Kendo strike attack, which should manage to reach Kerpymon. Just do normal mid-air slashes on the Cloud. With Chaos-Agunimon, stick to the Pyrodarts (Down + B) and use the Pyrotornado Attack (Up + B) on the storm cloud. It is -recommended that you use that move from the ground -- the same with Agunimon.

Hyper Digivolution special move:  Keep attacking your opponent constantly until yellow diamonds come out of it. Collect all those diamonds, until you see you have five diamonds in the top bar. When you have maximum digivolution Power, press A + B + Up and your Digimon will do a super special move. Many diamonds will fall out of the opponent after the attack.

Ancient Tag:  Depending on your final score at the end of the game, you will get a "Tamer Tag" which shows you how good you are. The normal tags go from rookie level to ultimate level. You can even get a mega level tag if you are very skilled. However, if your score is very high (at least 4223 points) at the end of the game, you will receive an ancient level tag. [Screenshot 1] [Screenshot 2]

Digimon recommendations:  You start with Agunimon, Lobomon, Kumamon, Kazemon, and Beetlemon .Some players are more effective then others. Agunimon has a high attack power and decent defense. He is somewhat speedy and his combos are easily summoned. He is best for beginners or first timers. Lobomon's attacks are powerful, but are very easily blocked and dodged. Combos and speed are the top sources of his power. He is recommended for intermediate players. Kumamon has freezing attacks which help make up for his semi-low attack power. However, he is best at fighting when Beast Spirited evolved. He is recommended for beginner or intermediate players. Kazemon has the lowest attack power, but has several abilities that make up for it. Her dash attack (Left(2) or Right(2) and B) can confuse an opponent, which is also very helpful. Press Jump(2) to make her jump higher, giving her a better advantage over her opponents. She is also stronger after Beast Spirit evolving. She is recommended for expert or intermediate players. Beetlemon has the highest attack power, but is slow and clumsy. When pressed down in the air, he slowly glides down, which can be helpful if you are trying to ambush your opponent. Nearly all of his attacks knock out level 2 and 3 Spirit Balls rather then the usual level 1, not to mention a few Ancient Spirits. Most all can be charged to generate more power. His Beast form is powerful, but not very moveable. He has a strong defense as well. He is recommended for beginners. Loweemon is extremely easy to play with and is very powerful. Shadow Meteor (Up + B) always confuses an opponent and Ebony Blast (Beast Spirit attack) does the same. He has an outstanding attack power, and his defenses are all but impenetrable. He is also very speedy. He is recommended for any player.