I have finished the game by completing all four meisters' routes. It seems we only need to finish the game to unlock all the MS because I have unlocked all!
Anyway, I haven't unlock the locked game mode in the Meister Mode. I saw on the net and the locked mode should be Time Attack while the 4th column in the Meister Mode is the Time Attack Ranking.
One more thing, besides 00 Gundam can be unlocked in the game after finishing Setsuna's route + anyone of other meisters' route,
I also unlocked Ahead which it's pilot is the masked Graham!!!
Bad news for this game is no co-operative mode in this game and the Versus Mode is like piece of shit! Sure Gundam Seed Destiny Zaft vs. Union is much much better than it!!!!!
Looking forward for a new and better Gundam 00 Season 2 game with improvements......
Hope it will be released in ps2 instead of ps3......