Use a memory card with a saved game file from Sonic Heroes. Select Story, Free Battle, or Online mode, then go to the trading machine and select the 'Search Event Files' option.
Billy Hatcher Demo Tape
At the title screen, hold G + B on a keyboard to see a Billy Hatcher video preview.
Chair In Lobby
Hold X and press A or B while standing in an online lobby to create a Photon Chair that matches your character's Section ID. Press A to move forwards or use the Analog-stick to turn. Press B to get rid of the chair.
Clippen Card
Use a memory card with a saved game file from Billy Hatcher.
Control Loading Screen
Use the Analog-stick to change colors and/or tap A to make a chime at the loading screen.
Dressing Room
Successfully complete both the Hunter and Ark storylines in Story mode (offline) to unlock the Dressing Room. It will disappear after each use, but will reappear again each time either the Hunter or Arkz storyline is completed once more.
Halloween Rappy Card
Use a memory card with a saved game file from Sonic Heroes.
Madam's Umbrella Card
Use a memory card with a saved game file from Sonic Mega Collection.
Nano Dragon Card
Use a memory card with a saved game file from Phantasy Star Online Episode 1 And 2.
Rage Card
Use a memory card with a saved game file from Sonic Adventure 2 Battle.
Sange Card
Use a memory card with a saved game file from Sonic Adventure DX.
Sonic Knuckle Card
Use a memory card with a saved game file from Sonic Heroes.