It contains timelines for all of the Amuro-Char era animated UC series, although 08th MS Team and War in the Pocket are integrated. Battle Universe is the most complete of the games. Battle Chronicles gives you extra perks if you have save data from Royale/ Tactics, hence why you may need to start at the beginning. Gundam Battle Royale/ Gundam Battle Tactics, Gundam Battle Chronicles, then Gundam Battle Universe is a game trilogy and you may need to get them all. It's a tactics game and knowing enough about Japanese to look up a few things (what mobile suit stats are what) would be recommended.
SD Gundam G Generation Portable was pretty good primarily because of the mobile suit selection. So you would have to import them, probably from play-asia. First thing is first they are all in Japanese if you didn't know that already.
