Collector interest
Sega's 1990 port of the famous arcade rail shooter, released in the US early in the Genesis's life. Extremely common loose, it stays one of the console's most accessible titles, which explains a minimal loose value. The dramatic jump to sealed examples comes from the scarcity of unopened boxes of a common launch-era game, quickly torn open and played. Desirability therefore concentrates on sealed stock, not the unremarkable cartridge.