If you want to toggle on a chain counter, which appears beneath the Chain Status box, push Z at anytime while playing the game.
Gallery 2 option
After finishing the game under any difficulty you will unlock the "Gallery 2" option at the "Appendix" menu. Alternately, accumulate at least ten hours of total game play.
You will start the game with three credits and earn one for every hour of play to a maximum of nine credits (six hours). Free Play mode is unlocked after seven hours.
Gallery 1 option
Finish trial mode without using any continues to unlock the "Gallery 1" option at the "Appendix" menu. Alternately, accumulate at least five hours of total game play.
Game mode option
Finish the game under normal difficulty without using any continues to unlock the "Game Mode" option at the "Appendix" menu. Alternately, accumulate at least twenty hours of total game play.
You can unlock this mode after playing the game for twenty hours. This mode adds an extra energy gauge that you recharge by annihilating enemies and use up while shooting. After you have absorbed a certain amount of same-colored shots you can unlock a special laser homing attack.
Practice and Conquest modes
By reaching a level without any continues you will unlock that level for these modes respectively. This means you have to reach level 3 in practice/conquest mode without any continues you will unlock that level. Bonus unlockables are released as you play the game for extended periods of time (cumulatively). Every hour you play you will unlock...
Sound test option
Finish the game under easy difficulty without using any continues to unlock the "Sound Test" option at the "Appendix" menu. Alternately, accumulate at least fifteen hours of total game play.
Control two players at once
With two wavebird controllers, set the receivers on the same channel and use one Wavebird on the same channel. You can then control two players at the same time. Set them side to side (horizontal) or (vertical) above each other by pushing them to the edges of your screen. If one gets wasted, you can quickly change color so you will have one...
Increase score permanently
Every time you continue, the last digit of your score goes up by one permanently. For example, if you continued once it is a "1", twice for a "2", etc. This is useful for gauging how much you have continued once the "Free Play" option has been unlocked.
Your ship can absorb bullets of the same color. The shots which you inflict cause double damage if they are opposite colors than your opponents. (You can change colors (between black and white at any time) If you are in white mode you can absorb white bullets and inflict double damage on black mode opponents.
Enemy and bullet patterns
Learning the patterns of your enemy and his bullet patterns will help gamers effectively pass through required zones. Memorization will become imperative when the difficulty rises later in the game. Remembering the color of bullets for an enemy will help you absorb an opponents attack rather than dodging for cover.