Super Robot Wars/OG2/Secrets

Secret Mecha

Unit	Requirements
Wild Wurger L	- Arado must shoot down 4 or more Gespenst MK-II M's during scenario 19, before moving next to Seolla. - Arado must have at least 50 kills by the end of scenario 26. - If you've met the required conditions, then Mai will sortie in it during scenario 27. - Have Mai shoot down 5 initial enemy units before player reinforcements arrive. You'll receive Wild Wurger L after the scenario is finished.
Ashsaber	- In scenario 10 on the Earth route, or scenario 13 on the Moon route, Echidna must be shot down, or forced to retreat. Lamia must then move to the square that Echidna was on right before she retreated. - Lamia must have 2, and only 2, battle encounters with Axel during scenario 19. - Lamia must have at least 53 kills by the end of scenario 24. If you've fulfilled the requirements, then Lamia will sortie in it during scenario 28.
Vaisaga	- In scenario 10 on the Earth route, or scenario 13 on the Moon route, Echidna must be shot down, or forced to retreat. Lamia must then move to the square that Echidna was on right before she retreated. - Lamia must have 1, and only 1, battle encounter with Axel during scenario 19. - Lamia must have at least 55 kills by the end of scenario 24. If you've fulfilled the requirements, then Lamia will sortie in it during scenario 28. - Can only be done on a second playthrough.
Huckebein MK-III R	- Ratsel must gain 15 more kills (in addition to what he starts out with) during scenarios 17 and 18. - You must obtain the Battle Mastery in scenario 30. - Bullet, Kusuha, Ryoto, Rio, Tasuku, and Leona's combined level total must equal 185 or higher by the end of scenario 33. - If the conditions have been fulfilled, then Ratsel's Huckebein MK-III Trombe will become the MK-III R.
Gespenst MK-II S	- Kai must have at least 55 kills, and must be level 33 or higher by the end of scenario 33.

Secret Weapons

Weapon	Requirements
Graviton Cannon	Viletta must defeat all of the enemy units by herself, with the exception of Yuuki, Carla, and Seolla during scenario 6. It'll come equipped on Viletta's Gespenst MK-II R during scenario 15.
Shishioh Blade and G-Impact Stake	During scenario 15, Silbelwind, Drukin, and Graterkin must be defeated. (Note: Graterkin MUST be defeated last in order to obtain these weapons. The order of the other two does not matter.)
Boost Hammer	Arado must destroy all of the initial enemies (Gunsects) during scenario 16 on his own within 4 turns. It will be obtained after the scenario is completed.
Shishioh Blade	Bullet must have at least 45 kills, and be level 18 or higher by the end of scenario 14. It will be obtained before scenario 18 begins.
Stealth Boomerang	Carla must be shot down at least once before scenario 31. It will come equipped on her Randgrith.
Neo Chakram Shooter and G-Impact Stake	Dygenguard must not defeat any enemies during scenario 30. The weapons will be obtained after you decide which route to take during the following split.

Secret Parts

Parts	Requirements
Steel Soul, Hero's Mark, and Custom CPU	During scenario 15, Silbelwind, Drukin, and Graterkin must be defeated. (Note: Graterkin MUST be defeated last in order to obtain these parts. The order of the other two does not matter.)
2nd Steel Soul and 2nd Hero's Mark	Finish the game once, then on subsequent playthroughs you will gain these items automatically at the end of scenario 33.

Misc. Secrets

Secret	Requirements
EX-Hard	Obtained after finishing the game once. In this mode PP and money are carried over, weapons cannot be upgraded, all of the pilot stats and skills cost double of what they do normally, the difficulty is on hard regardless of how many Battle Masteries you've obtained, and all enemy units are stronger than normal.
Special	Obtained after finishing EX-Hard once. In this mode PP and money are carried over, all units have ten levels of upgrades for all stats, and you obtain one of each weapon and part.
Sound Select	After finishing the game once, go into the system option and press down, up, left, right, L, and R. You'll then be able to listen to all of the BGMs that are in the game.