Fighting mixed teams with special outfits in tag battle mode:
Just press start button when selecting tag battle mode. You will face randomly paired teams dressed in alternate costumes instead of fighting default teams i.e. Kasumi and Hayabusa, Bass and Tina and so on.

Hidden Characters:

Unlock All Costumes:
Play in Story Mode for all the main characters, and Time attack for Hitomi, Bayman, and Tengu.

Unlockable features:

Collection Mode:
Play through survival mode to unlock Collection Mode. This lets you view the various items you collect through Survival mode.

Time Attack Medals (Single Player):

Unlock all Costumes, CG Gallery, Booster Disk and DOA Episode:
To unlock all costumes, the Booster Disk and CG Gallery as well as the DOA Icons episode, play survival on any difficulty setting and collect all 66 items.

Unlock Character System Voices:
You need to beat Exercise (in Sparring) mode with certain characters to unlock certain voices. Note: "System Voices" are the voices that say "Fight!", "K.O.", "Winner!", etc. and are changed at Settings>Game Settings>Others

Extra Config Option and Ring Size:
To unlock extra config option and ring size for DOAU1 beat the arcade mode once with anyone.

Danger Bounce:
To open Danger Bounce in the Extra Config enter the initials DOA when you finish Arcade Mode

Extra Config Option Danger Zone:
Finish Survival Mode

Extra Config Option Fighting Order:
Finish Time Attack in under 5 minutes to unlock Fighting Order in extra config

Hidden Xbox and Christie photograph in "The Crimson":
In the level "The Crimson" if you knock someone through the glass window on the upper level, you will go to another area. In this area is a picture of Christie from "Dead or Alive 3" on the wall, as well as a Prototype Xbox connected to a T.V. If you hit someone into the Xbox and T.V., the Xbox will light up and the Xbox logo will be displayed on the screen.

Lighting up Zack's costumes:
On Zack's C3 and C7 costumes, if you taunt during a match, they will light up for the round. If you taunt again, it will turn off.

Genfu Hat Trick:
On Costume 3, use the Tenseiha appeal to make him take off his hat. If you win the battle, he will put his hat back on and say something different.

Perfect round victory poses:
In all modes (except Story Mode and Sparring Mode), if you play a perfect round (in other words, don't lose any health), you'll get a victory pose that you can only see if you play a perfect round. Some characters will even have a second "Perfect Round" victory pose if you can get two perfect rounds.

Adjust Camera during Celebration:
During the ending celebration after each battle, you can move the camera. By pressing either the left or right trigger, you can turn the screen, up to, 90 degrees clockwise or counter-clockwise. By using the right analog stick up or down, you can move the screen over or under the character.

Alternate Level Select:
Press X on the following stages to play a variation of that level.

The Aerial Gardens
The White Storm
The Great Opera

Extra Collection Items in Survival Mode:
While playing in survival, if you punch or kick your opponent while they are lying on the ground, they will drop a collection item. Note: Certain characters can only punch opponents that are on the ground and certain characters can only kick opponents that are on the ground.

Alternate Hairstyles:
With Kasumi and Lei Fang, they have up to 4 different hairstyles; available by pressing up to 4 different buttons corresponding to the hairstyle.

For Kasumi, all 4 hairstyles are accessible for all [20] costumes.

A: Loose Hair.
X: High Ponytail.
Y: Low ponytail.
White: Low braid.

For Lei Fang her hairstyles are a little different.

C4: A/White: Ponytail.
X: Loose hair.
Y: Braids.

C6/C8/C13:

A: Bun.
X: Loose hair.
Y: Ponytail.
White: Braids.

Every other costume:

A/Y/White: Braids.
X: Loose hair.

Same kind of outfit as yours for your opponents in "Story" mode:
Select Story mode pressing "start", not "A". Select the character and the desired costume pressing "start" button, always "start" button. By this way, all the opponents in the game will wear the same outfit as you, but this doesn't work for all characters. For example, if you select LeiFang with the "Xbox" dress, all the other girls you encounter in the game will wear the "Xbox" dress too. Same happens if you select the "Black" costume, "White", "Bikini", etc, or other types of costumes that shares similarities with the rest of characrter's outfits.

Zack's Snow Board:
In the level The White Storm, use Zack's move "Heart Breaker" while your opponent is at the edge of the slope at the beginning of the level. If done properly, following the move, Zack will lay out the enemy's body, and use it as a snowboard down the hill.