Expert survival mode
complete the game in survival mode to unlock expert survival mode
M1 Rune
complete game on (easy difficulty) setting to unlock the M1 Rune
M3 Rune
complete the game on the (normal difficulty) setting to unlock the M3 bonus
M4 Rune
complete 10 co-op matches to unlock the M4 Rune
M2 Rune
complete a versus mode match with 4 human players to unlock the M2 Rune
M6 Rune
complete 20 co-op matches to unlock the M6 Rune
M8 Rune
complete story mode on the (hard difficulty) setting to unlock the M8 Rune