Press Select + Start when the victory message appears in the arena to add the defeated AC's emblem to your list.
Defend Lawdas Factory mission: Hidden part
When the big laser destroys the missile in the center of the map, jump down and look for the part. The part is an extension CWEM-RT16.
Defend Mirage HQ mission: Hidden part
When the mission starts, turn around and boost towards the helicopter landing site. Look around the landing site to find the back stealth missile, MWM-SM36.
Defend Solar Power Plant mission: Hidden Part
After you defeat all the enemies on the outside of the power plant, you should get a notice about enemies inside the plant after you enter. Clear the first floor. When you go down the ramp at the end of the first part, you will see a fork. Go to the left. There should be the part at the end of the room. The room is on fire. The hidden part is the KWEL-EJ22 anti-missile.
Destroy AI Prototype mission: Hidden part
On the ground in a small room closed off by destroyable gates is the left arm part KSS-SS/707A.
Destroy Cargo Transport mission: Hidden part
Use a very fast AC for this mission. When you see the first intersection, instead of turning right with the transport, turn left and jump behind the middle barricade and get the part. It is the inside floating mine, CWI-FMHS-30.
Eliminate Bio Weapon mission: Hidden part
At the first room, turn left and keep shooting all over the wall. When you reveal a secret passage, follow it to the part. It is a PRAYYING BLADE.
Eliminate Rioters mission: Hidden part
When you reach the most top level and enter, a box will be destroyed by enemies. On the floor is the inside part KWL-RJ/60.
Explore Unexplored Region mission: Hidden part
Go into the crater to find a plane. Shoot the back end of the plane to destroy that section. Inside the plane is the back part MWC-OC/30.
Infiltrate New Base mission: Hidden part
In a cave in the middle of the map is the extension part MWEM-R/36.
Investigate mission
Go to the first door, unlock the control panel, then search for the second one. In the room where there is a ventilation duct, shoot the duct. Fly up, then go down into the other room it leads to. Destroy all the boxes to find the left arm part KWG-NHZL60.
Protect Part Transport mission: Hidden parts
Wait until the plane lands, then get behind the it. Shoot the back end until the door explodes. Press Circle next to the part to get the right arm part CWG-ARF-180. When the mission starts, turn around and go to the left storage room. Go inside and get the part. It is the left grenade rifle CWGG-GRSL-20.
Search Vilius Laboratory mission: Hidden part
Search the bottom of the deepest pit to find a part guarded by a MT. It is the left arm part MWG-KPL/150.
Secure Fortress NK-432 mission: Hidden parts
Find the room filled with lots of boxes. Do not destroy any boxes with red triangles or any boxes on top of red triangle boxes (the top box destroys the one under it, etc.). The right arm part MWG-GS/80 can now be found on the ground. Use your map near the first target to find a secret passage behind the wall. Destroy that part of the wall and follow the secret passage until you reach a room with one box. Destroy the box to find the head part MHD-MX/BEE
Takeover New Fortress mission: Hidden part
When you battle against the two ACs fly up into the giant hole in the ceiling. When you look up, there should be a pipe that runs from one side to the other. On top of the pipe is the FCS part PLS-SRA02.
Prototype parts
If you use a certain type of leg part (light weight leg, middle weight leg, hover, etc.) for enough missions, a "prototype" part will be unlocked in the shop. The prototypes are usually good. This may also be the case with other parts as well.
Bonus parts
For every mission you get an "A" or "S" rank on, you will get a special bonus part. The following are the other requirements to get bonus parts at the store.
MRL-MM/001: Reach AC rank "D"
MWGG-HNRL-100: Reach AC rank "C"
KAW-SAMURAI2: Reach AC rank "B"
MAM-MX/MDD: Reach AC rank "A"
MBT-NI/GULL: Reach AC rank "S"
CWI-DD-30: Defeat E-21 at the Arena
RGI-KDA01: Defeat E-15 at the Arena
KWG-NHZL30 : Defeat E-8 at the Arena
CWR-M70: Defeat D-7 at the Arena
CWM-BM60-1 : Defeat C-7 at the Arena
MWG-SRFE/8: Defeat B-4 at the Arena
MCL-SS/RAY: Defeat A-3 at the Arena
MWG-MG/FINGER : Defeat A-1 at the Arena
CWM-HA40-8: Defeat rank 1 in Extra Arena
MWG-HGB/108: Rank "S" in all missions
KGP-ZXV1: Complete all missions
CCL-02-EI: Complete 10 missions from Crest
MCM-MI/008: Complete 13 missions from Mirage
KEEP-ELIX: Complete 7 missions from Kisaragi
Op-Intensify (All Abilities): Obtain 99% completion of the game.
Easy money
Find any mission that has an advance payment. Start the mission and immediately abort it. After this is done, you will see your earnings displayed in two boxes. One box is for your new money amount that was earned and one for the deductions for repairs, ammunition, and the special deduction in the event that something was destroyed that was not supposed to. Note that there is no deduction, and you will get the amount that was promised to you in advance. Make sure to save your game before you do this, as the game will end if this is done too many times.
Easy Arena wins
Select the Trene City area. When the battle begins, there is a big building directly in the middle of the Arena floor. Boost up to the top of the building and pummel the opponent AC full of rockets or other types of ammunition that can lock on. If you are unable to boost up the entire way, there is a ledge halfway up. Rest there momentarily, then boost the rest of the way. Weapons that are the most effective are the small rockets and/or vertical missiles. There are some enemies that are too fast to do this to; they move to much to get a lock on. If this happens, when you start, boost West and position yourself in between two buildings very close to the border. Most of the enemy ACs will not go behind because they will lose. They will just move back and forth trying to get a fix, but will not approach you if you are very close to the border. Pop in and out from behind the building and shoot various rockets and missiles as the ACs are moving around. It is slightly time consuming, but a very easy way to boost ranks early. Take your opponent to the Arena stage. Have Hectos Rockets and the left hand grenade launcher equipped. When the battle starts, start stepping backwards, making sure not to turn or alter where the aimer is pointed. Switch weapons to the Hectos Rockets and keep firing those with the grenade launchers. The opponent will just follow your steps, and will not move from the line of fire. If they get too close, start to fight normally; they will have low AP at this point.
