Unlock Characters in Story Mode
Unlock the following secret playable characters by beating Medium level
difficulty:
1853 Wild West:
The Colonel
1972 Atom Smasher:
Khallos
1920 Aztec Ruins:
Stone Golem
1938 Chicago:
Big Tony
1990 Siberia:
Hybrid Mutant
2019 NeoTokyo:
Sadako
2280 Return to Planet X:
Ozor Mox