i've spent 103 hours on SD Gundam G Generation World for the PSP and i've only unlocked 95% of the mechs...
5% mechs is about around 30 more mechs to unlock and about 10 missions to go xD
Nice. At least this way you wont get bored for awhile.
I'm going crazy over Patapon 3, Dissidia Duodecim and 3rd Birthday. But Patapon 3 has my focus. Simple and addicting game.