Fight hidden boss...
	Second loop...
	Various Achievements...

To fight the hidden boss at the end of stage 3, you must finish the stage without dying and then finish the original boss at the end of the stage off with either a special move or a bomb. After the point total is tallied for the stage a new boss will appear.

To unlock the second loop you must collect envelopes dropped by various King of Fighters characters in the five stages of the game. The first four can be collected during any playthrough and as long as you've done this, you can get the final one using stage select. When you go to collect the fifth envelope, you must finish the entire stage and boss without dying. After this is accomplished you will play through all the stages again on a harder difficulty and there will be an alternate final boss after the boss of the fifth stage is complete.

Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock	Points
300 Combos	Complete 300 Combos in 1 stage! (1Player Game)	10
Countdown to Destruction	Clear Stage 5! (1Player Game)	20
Crimson World	Taunt 30+ Times in 1 Play! (1Player Game, No Continues)	10
Don't Use the Bomb!!	Clear through Stage 5 without Using the Bomb! (1Player Game)	20
Final Stage	Obliterate the Final Boss! (1Player Game)	20
KOF Into the Sky	Try It Out!	10
Prove Your Ability	Clear Stage 1! (1Player Game)	10
Resurrection	Clear Stage 4! (1Player Game)	20
Separate Fates	Clear Stage 3! (1Player Game)	20
The Edge of Truth	Clear Stage 2! (1Player Game)	20
The Temptation of the Gold Medal	Get 50 Gold Medals in 1 stage! (1Player Game)	20
Turning the Tables!	Obliterate the Intruding Boss! (1Player Game)	20