From Sega Retro
6-Pak is a compilation of Sega Mega Drive/Genesis games released in June 1995, during the console's decline. The cartridge contains 6 of Sega's most successful games from the early days of the Genesis; Sonic the Hedgehog, Golden Axe, Revenge of Shinobi, Streets of Rage, Columns and Super Hang-On. The in-game menu features digitized box art of the original games. It also came with a 67-page manual that contained the complete instructions for all six games. Interestingly, the artwork used on the box for Columns is not from the Mega Drive version, but instead the Master System edition of the game.
There is a similar compilation in Europe called Mega Games 6 but it is broken up into three volumes. Each containing some games which are unique to each collection.