Unlock Old Red:
     To  unlock  Old  Red you have to successfully complete the career
mode with Red Rocker.

Unlock Old Blue:
     To  unlock  Old Blue you have to successfully complete the career
mode with Blue Bomber.

Unlock Ben Hurt:
     To  unlock  Ben Hurt you have to successfully complete the career
mode with with Slamuri.

Unlock Sir Haxalot:
     To  unlock  Sir  Haxalot  you  have  to successfully complete the
career mode with with Head Case.

Unlock Tywrenchula:
     To  unlock  Tywrenchula  you  have  to  successfully complete the
career mode with Stakeout.