To unlock an additional mobile suit for a certain Gundam, complete story mode with that Gundam.

To unlock Master Asia and Master Gundam, complete Domon Kasshu's Original mode.

Unlock the following suits by performing the corresponding tasks:

SUIT - HOW TO UNLOCK
Char's Gelgoog suit - Complete amuro ray's offical mode.
Char's Zaku II suit - Complete char aznable's offical mode.
Hyaku Shiki suit - Complete char aznable's offical mode mission 4.
The O suit - Complete kamille bidan's offical mode.
Qubeley suit - Complete judau ashita's offical mode.
Gundam ZZ suit - Complete judau ashita's offical mode.
Master Gundam suit - Complete domon kasshu's original mode.
Gundam Epyon suit - Complete heero yuy's original mode.
Black Gundam Mk-II suit - Complete both kamille bidan's and heero yuy's original modes.
Black Qubeley Mk-II suit - Complete both judau ashita's and domon kasshu's original modes.
Red Qubeley Mk-II suit - Complete both elpe ple's and rolan cehack's original modes.
Musha Gundam suit - Complete all six amuro ray's, kamille bidan's, judau ashita's, domon kasshu's, heero yuy's, and rolan cehack's original modes.

Unlock the following pilots by performing the corresponding tasks:

PILOT - HOW TO UNLOCK
Amuro Ray pilot - Complete amuro ray's official mode.
Kamille Bidan pilot - Complete kamille bidan's official mode.
Judau Ashita pilot - Complete judau ashita's official mode.
Char Aznable pilot - Complete char aznable's official mode.
Paptimus Scirocco pilot - Complete paptimus scirocco's official mode.
Haman Karn pilot - Complete haman karn's official mode.
Master Asia pilot - Complete domon kasshu's original mode.
Milliardo Peacecraft pilot - Complete heero yuy's original mode.
Jerid Messa pilot - Complete both kamille bidan's and heero yuy's original modes.
Emma Sheen pilot - Complete both char aznable's and rolan cehack's original modes.
Elpe Ple pilot - Complete both judau ashita's and domon kasshu's original modes.
Ple Two pilot - Complete elpe ple's original mode.
Roux Louka pilot - Complete both judau ashita's and haman karn's official mode.

ACHIEVEMENT - HOW TO UNLOCK
Official mode - 1 Character (25 points) - Beat Official mode using 1 or more characters.
Official mode - 3 Characters (50 points) - Beat Official mode using 3 or more characters.
Official mode - All Characters (75 points) - Beat Official mode using all characters.
Original mode - 1 Character (25 points) - Beat Original mode using 1 or more characters.
Original mode - 8 Characters (75 points) - Beat Original mode using 8 or more characters.
Original mode - All Characters (100 points) - Beat Original mode using all characters.
Character Gallery Complete (75 points) - Unlock all characters in the Character Gallery.
Mobile Suit Gallery Complete (75 points) - Unlock all Mobile Suits in the Mobile Suit Gallery.
50 Total Missions Complete (50 points) - Complete 50 or more Total Missions.
100 Total Missions Complete (75 points) - Complete 100 or more Total Missions.
Total Shot Down 50000 (50 points) - Shoot down 50,000 total enemies.
Total Shot Down 100000 (75 points) - Shoot down 100,000 total enemies.
Pilot Level Max (75 points) - Get a Pilot Level of 30 for a character.
Mobile Suit Level Max (75 points) - Get a Mobile Suit Level of 10 for a MS.
All Skills Acquired (100 points) - Obrain all skills for a character.