Get emblems
yes
Collect emblems
Get a lot of emblems
gold egg
You need to have at least iver 25 emblems to get a green egg in sonic adventure 2 battle
No
You have to buy it
Collect emblems
You buy them at the black market @ chao kindergarden.
Collect a lot of emblems
No, Sonic Adventure 2 is only on Dreamcast and Gamecube as Sonic Adventure 2 Battle.
You need a gameboy advance and a dual link