Unlocking the two hidden characters in the game is actually quite easy. To be able to play as either Mega Man or B. B. Hood (a little girl that looks like red riding hood and carries an arsenal in here basket and rides a scooter) all you have to do is beat the game. You can beat the game using any character and on any difficulty level. Once the characters are unlocked you select them by pressing right or left, off the screen at the character select screen.

Again all you have to do is beat the game once using any character and on any difficulty level (we suggest the easiest level to make it go quick) and when you get to the Main Menu just through the menu until the Gallery is highlighted. Now just select it to see all kinds of character art and other art bits from the game. It's actually pretty cool since you can zoom in on the art and check all the details.

Cammy is the only character in the game with an alternate outfit.

To select it go to the Character Select screen and then highlight Cammy. Now press Up or Down to make the new costume appear.