ALL high scores are without continue.
Continue based games tend to have endings.
Any world class players are a game that has continues won't need them. I can (for example) make it through Star Wars Trilogy on one life, sometimes without being hit.
So getting a world record score at Star Wars Trilogy, Crystal Castles, Road Blasters, etc is based on playing a PERFECT game, or as close of one as possible.
Non continue games are often endless (or go until a crash at a certain level).
World class player's at non-continue games can often play indefinitely. That makes these games more of an endurance event.
So getting a record score at Robotron, Defender, or Space Invaders simply involves the ability to stay at the machine for a long enough period of time.