These are only that which I have personally seen unlocked, there are many more rumored, but I have yet to confirm them.*For most of these you'll need to have beaten the mission mode at least once.Unlocking EFF Shield(like that of Gundam and GM's)-After completing the game, successfuly complete practice mission 1 with Austin's Zaku IUnlocking Lt. Commander Garret Schmitzer with his MS-05S Zaku I custom-Simply Complete the mission mode onceUnlocking Char Aznable and his MS-06S "Red Comet" Zaku II Custom-On simulator mission I "Practice" receive an A or an S rankingFor Garma Zabi and his MS-06Fs custom-Receive an A or an S in simulator 2-Practice IIFor Ranba Ral and his YMS-07b Gouf-Complete the entire mission mode a second time up through at least mission 8For Gaea of the black Tri-Stars and his MS-09 Dom-Complete up throug mission 12 a second timeFor Agar in his guncannon completecomplete mission 10"Attack jaburo" a second timeIn addition, complete simulations27 through 31 with an A or S to receive Agar;s RX-78-4 Gundam madrockFor Sayla Mass in the RX-78-2 gundam, receive a C or less in three seperate EFF simulation missionsFor Amuro Rei, in the RX-78-2 receive an S in all EFF missionsI know Kai and hayato are selectable, but am unaware of precisely how to achieve them, if all of the afformentioned is completed, you should receive tham as well.