Unlock Black Costume:
Complete 100 City Events and all Combat Tours, and collect all Tokens.
Unlock Peter Parker Costume:
Complete 50 City Events, collect 50 Tokens, and win the 4th race against Johnny Storm.
Unlock Parker Hoody Costume:
Complete 75 City Events, collect 75 Tokens, and complete 32 combat tours.
Unlock Spidey Wrestling Costume:
Complete 30 City Events, collect 30 Tokens.
Unlock Arachnoman Costume:
Complete 90 City Events, collect 90 Tokens, and complete 48 combat tours.
Unlock Venom Races and Switch Hero option:
Complete all story mode missions.
Unlock Medium City Event Difficulty:
Complete 10 City Events and complete Chapter 6.
Unlock Hard City Event Difficulty:
Complete 20 City Events and complete Chapter 8.
Unlock Medium Combat Tour Difficulty:
Complete 8 Combat Tours after completing Chapter 4.
Unlock Hard Combat Tour Difficulty:
Complete 12 Medium Combat Tours.
Unlock Insane Combat Tour Difficulty:
Complete all Hard Combat Tours.
Thanks to Revolution readers octavious and slpntz007!