sare these just NES versions or are they arcade games? I know crystalis is a nes game but id rather not buy nes games all over again ......

I have gone through most games and they do have both the arcade and console port.

So far it seems the only time the console version isn't available is when SNK wasn't involved with it, for example there was a port of Time Soldiers on the Master System but it was made by Sega themselves and is not available in this set,

Just beat Guerilla Warfare and the achievement didn't unlock.