255 enemies destroyed using a flight unit.

Emil's shop used for the first time.

Complete the alien ship.

Clear 10 Sonic the Hedgehog 2 Missions with an S rank

Clear Sonic the Hedgehog 2 in either Anniversary or Classic Mode

Complete the amusement park ruins.

Complete the desert area.

Arrive at the city ruins.

Clear 10 Sonic CD Missions with an S rank

Turn into Super Sonic

Clear Sonic CD in either Anniversary or Classic Mode

Travel to the past or future in Sonic CD