All Mission compete unlockables.
Beating all missions and getting a S-Rank in all of them will unlock various parts. Competeing 11 missions with a certain type of leg part will unlcok a new leg part.

CCL-02-E1 Compete all CREST missions.
CLC-D4ZTSL Complete 11 Missions with Catepillar Legs
CLH-04-SOD Complete 11 Missions with Heavyweight Humanoid Legs
CLL-03A-SRVT Complete 11 Missions with Lightweight Humanoid Legs
CLM-02-SNSKA1 Complete 11 Missions with Middleweight Humanoid Legs
KEEP-ELIX Compete all KISARAGI missions.
KGP-ZXV1 Compete all Missions.
MCM-M1/008 Compete all MIRAGE missions.
MLB-MX/008 Complete 11 Missions with Reverse-Joint Legs
MLF-RE/006 Complete 11 Missions with Quadruped Legs
MLR-MX/LEAF Complete 11 Missions with Hover Legs
MWG-HGB/108 Get S-Rank on all missions.


Ranking Unlockables.
Reaching certian ranks will unlock certian parts.

CWI-DD-30 Defeat Arena Rank E-21
CWM-BM60-1 Reach Rank C-7 In The Arena.
CWR-M70 Reach Rank D-7 In The Arena.
KAW-SAMURAI2 Reach Raven Rank B.
KWG-NHZL30 Reach Rank E-8 In The Arena.
MAM-MX/MDD Reach Raven Rank A.
MBT-NI/GULL Reach Raven Rank S.
MCL-SS/RAY Reach Rank A-3 In The Arena.
MRL-MM/011 Reach Raven Rank D.
MWG-MG/FINGER Reach Rank A-1 In The Arena.
MWG-SRFE/8 Reach Rank B-4 In The Arena.
MWGG-NHRL-100 Reach Raven Rank C.
RGI-KDA01 Defeat Arena Rank E-15

Get Arena AC Emblems
Press Start and Select while looking at a defeated Arena AC. You'll hear a tone telling you that it worked.


Getting the MWC-OC-30 back weapon
The MWC-OC-30 back part is in the mission ''Investigate the Unexplored Region''. I suggest taking a heavy tank armed with a long range weapon to take out the pesky heavily armed bazooka launching MTs. But make sure you have a fast weapon, such as the LQ-15 or the CNG-300.

First take out all the fast moving MTs. Then when the heavy MTs are left. Go to the center of the map where the wreckage of the plane is. Blow up the back and go inside, the OC-30s will be inside on the left.

Then after you defeat the MTs, two unknown ACs will come after you. I suggest getting in the whole, the getting out of it and getting to the opposite side of the plane opening, VERY QUICKLY! If you're lucky the moron tank will get stuck in the plane leaving the other, lighter AC to you. After you're done with the AC, go after the other, it doesn't fire much, just unload all your ammo on him and he'll die quick.

After the missions over you should get a hefty sum of money and two MWC-OC-30s. If you're low on money sell them, they go for 99,000 a piece.


Getting the MWG-MGL-300 left arm part
Make sure you have the MRL-MM/001 radar part gotten from getting D rank. It will clear up the radar error and lets you see the good tanks from the bad, good are green and red are bad. You will still target the good tanks.

Make sure you have a good weapon like a bazooka or the KARASAWA to get that sweet one hit kill. Make sure too look at your radar to make sure you're not aiming at a friendly.


Obtaining the MWB-MX/WAKE back part.
In the mission Mission: Test New Technology in Zone 5 - Neo Central, you'll have four parts of the mission to complete to get this part. Equip the NER Core, the longest range FCS, the Sniper Rifle with 80 rounds, and some Hecto Rockets.

First, you have to dodge all missiles fired upon you without attacking the MTs firing them. To do this easily, at the start of the mission, Overboost (Don't worry about running out of energy, the part you're testing makes it hard to do so) to the far transport ship and stay there. The missiles can't reach you from there.

After the timer runs out, you can begin attacking the MTs that fired the missiles upon you, but destroy them quickly. The Sniper Rifle should take them down in one hit.

Next, you'll have to deal with a bunch of Aerial MTs that decided to barge in on the mission. Dispatch them with the Sniper Rifle and ready yourself for the Massive MT. Aim carefully though, they're pretty fast.

Lastly, if you've met the requirements, you'll be attacked by the Massive MT. It's pretty easy though, just stay to its side or behind it and fire the Hecto Rockets. After you destroy it, you'll be rewarded with the MWB-MX/WAKE part. It adds 5000 to the power of your boosters