Boss battle mode
Play the Wisdom Headquarters level and proceed through until you have enabledthe main elevator. Go into the library on the unrestricted side and go upstairs. The door at the top should be open. Then go upstairs and exit out onto the balcony. Jump onto the chandelier, then go on the other balcony. Then go into the room on the other side and beat both enemies. Get the piece of paper and you will have the Boss battle mode option available.

Bonus weapon
Finish the game under any difficulty setting. Then save the game after the credits are done. Then reload the saved game to begin with a new double dagger weapon in addition to your original two weapons at their levels in the prior game you played.

Survival mode
Play level 1 and make it through the subway when you need to retrieve both Legacy Drives for the Lightning Rod. When you get out on the other side, go into the alley that has the fence with a junkyard on the other side. Walk up to the fence. Press Triangle when equipped with the Lightning Rod and quickly change to your hands to grab on to the top of the fence. Jump over to the other side, then go to the wall that has the ladder on it. Climb up the ladder and reach the top of the building. Once there, you will locate a piece of paper hovering above the ground. Walk into that paper. A message stating that survival mode has been made available will appear. Then save the game, then go into the bonus option at the main menu to use the new option.

3 minute battle mode
Play the China-town level after you have gotten the Katar. Now climb up the Chinese house that has the large flame on the porch. When you are up there, someone will surprise attack. Just kill him and go to the opposite side of the part you climbed up to. Then go to the back of the house, but stay on the balcony. Jump to the building on the far side and look around for a second piece of paper. Walk into it, and you will have the 3 minute battle mode option available.

Bonus modes
Finish the game under any difficult setting to access the "Survival" and "3 Minute Attack" options.

Hints & Tips

Beating Zera
When you are fighting against Zera for the second time, there is a ggod chance to keep track of her location when she replicates by simply holding L2. Also, if your crossbow is at level 3 or above, you have a chance of hitting her for some good damage.

Spiral lightning
When you are playing the final level and are fighting against Alga in his human form, he uses different kinds of Legacy Drives. Once he has used the Lightning Shower use the Katar's Legacy Drive. When you hit the lightning at the same time he uses the Lightning Shower, you will watch explosion of spirals of thunder and electricity that do a lot of damage to Alga's health.