If you have a save from Gundam Assault Survive Demo , create a character and go to the shop to "purchase" an item that costs 0G -- that will give you 250,000G.
Gundam F91
Use Heavy Gun and G- Cannon 5 times, with Seabook Arno as the pilot if just using the two MS is not enough...
Obtain 100,000G
If you have a Gundam Battle Tactics/Chronicle/Universe save data, go to the shop and get the items that cost 0G in the tab marked "Secret". You will get 100,000G for each.
Obtain 250,000G
You need the Gundam Assault Survive Demo save to unlock this bonus. After creating your character.Go to the shop and scroll down to the bottom option ,you will see an item that costs 0G that will give you 250,000G.
Providence Gundam
Use Rau's GuaiZ Custom and Rau Le Creuset at least ten times in versus or mission. To unlock Rau's GuaiZ Custom, first buy the development plan of Guaiz Custom. Equip normal GuaiZ with RESERVE MAGAZINE parts that costs 582.000 (S type) and upgrade the normal guaiz until it reach 4500 TP. After that, go to the shop and GuaiZ custom become available for sale.
Unlock Freedom
Beat mission 18 (Owaranai Ashita he EX) + use Kira (Zaft) 5 times That mission is an EX stage, and you don't need Kira (Zaft) to pilot Aile Strike. After clearing mission 18 just to go VS battle mode and set the time limit to 1 minute using Kira (Zaft) as your pilot 5 times.
Unlock Justice Gundam
Use Asuran in his Aegis Gundam 10 times. This can only be done if you complete some missions in Seed tab.