See these Contra games for the exact same use, or lack thereof, of the colon in the title between the actual name and packaging:

http://en.wikipedia.org/wiki/Contra_III:_The_Alien_Wars
http://en.wikipedia.org/wiki/Contra:_Hard_Corps
http://en.wikipedia.org/wiki/Contra:_Legacy_of_War
http://en.wikipedia.org/wiki/Contra:_Shattered_Soldier
http://en.wikipedia.org/wiki/Hard_Corps:_Uprising