Successfully complete the game and save when prompted. Load the saved game file to begin with your level, items, and accessories from the previous game.
Achieve all "A" ranks in the first five chapters to unlock a bonus mission where you must face Roy Mustang; defeating him is easy if you are level 25 or higher.
While characters are talking and there is a dialogue box, hold L3 to make it disappear, allowing you to only hear the character's voices.
When you transmute a weapon that can be leveled up (for example, the shurikens, gauntlets, bombs, etc.), if you use all its ammunition except for one, unequip the item, then level it up and its ammunition will be restore.
In Chapter 5 at Bord'wan, in certain areas there will be an unlimited supply of floating golems. Some are worth 10 experience points and others worth 80 experience points. This is a good time to train because there is a save point nearby.
There is additional cat to the right of the secluded house just before you find Lutinit Havoc. After you hear the gunshots from the door, go out the front (not near the save point). There will be a yellow cat in a box to the right behind a box or trash can.
While you are following Bald (the person who Ed thinks blew up the military car), go left when you first enter the sewers. There will be an object, and behind it is a cat in a cardboard box. Walk up to it and short intermission sequence will begin. Al will look at it, and take it while Ed is not looking. Equip this as one of Al's accessories. When you are not fighting, stop and call Al over. If you do not move for a few seconds, Al will decide to sit down, and a few seconds after that, the cat will meow and the word "-M-e-o-w-" will come out of Al's body.
Successfully complete the game and save when prompted. Load the saved game file to start in Lior fountain plaza. Look around after the dialogue scenes are over. There is a place in Lior fountain plaza where Armony is taking care of the kittens that you have. When you try to attack, a scene will start showing each of the kittens you have meowing.
Press Away + X.
You will enter a room that has a group of eyes on the walls. This is the room where the final battle will take place, against Crowley. When the battle begins, attack him repeatedly; your sword works best. When you can, use your rage, as it does a lot of damage to him. Counter his attacks as much as possible, but sometimes he will counter your counter attack. Press R2(2) and you will counter his counter and hit him. After his life bar is empty, he will talk about how he will not give up, and how he has to do this for Elma. He will then use the elixir to turn himself into a giant golem. Watch out for his attacks and let Al help you. Use your sword combos (for example, Square, Triangle(3)) to slash him. He will fall on the ground. This is the time to use the foot swipe. After he is defeated, Roy, Hawkeye, and the man with the muscles will appear and take over. At this point, you must destroy the stone. Once in the room with the crimson elixir, Ed will touch the stone and fall unconscious and his mind will go inside the stone. When you are there, you will be in some sort of white void. Just run to each of the red orbs. They are memories from the King of Lebis, and memories from Crowly and his Elma. Transmute the spikes on the outside of the circle. When Ed and Al transmute it, the stone will break, and Crowley will be defeated to be in peace with Elma.
Once the Boss sprays out eggs, transmute them before they turn into Gomes.
Get to where Scar blows off Ed's right arm in Roy's office, when everybody is picking on Ed. After Roy's comment "Useless, positively useless", Ed screams. Look at were Ed's name is supposed to be. It now reads "Useless, bratty, shrimp".
In Loir, when you are talking to the person that owns the food place and the camera goes to Ed and Al, wait a minute. Armory from Fullmetal Alchemist And The Broken Angel will walk by, look at the store, then walk off. Additionally, in the first fight against the Cornello Cultists, look in the right alleyway. At the back there is a wanted poster with a character from Fullmetal Alchemist And The Broken Angel.
After starting a new game, as mentioned previously, you can see Armory walk by when Ed and Al are talking to the people at the little restaurant (where you hear the religious broadcast by Father Cornello). After that, go up the street and you will encounter the man by the fountain of wine. After you grab his elixir, go left. There will be a shop in the left-hand corner of the dead end. Just before that will be a group of flower pots and Armory.
Start a new game in Lior. Go to the building left of the first save point; it will be a post office. Look inside the window to see the back of Gluttony. To his left will be Lust; you can only see the back of their bodies.