Designed by Gunpei Yokoi, the revered creator of the Game Boy, Dr. Mario is one of the most popular and acclaimed puzzle games of all time, selling over five million copies on the original monochrome handheld, and spreading to nearly every Nintendo system to date, from the Nintendo Entertainment System to the Wii.

  

In Dr. Mario, Mario has hung up his plumber’s toolbelt in favor of donning a doctor’s lab coat inside of the virus research laboratory at the Mushroom Kingdom Hospital. Nurse Toadstool tosses Mario vitamin capsules, and his task is to rotate them to match four of the same color in a vertical or horizontal row with the Viruses that contaminate the beaker. Mario must not prescribe too many pills, or else the Viruses will become immune, and he’ll wind up in the middle of a messy medical malpractice lawsuit!

A Game Boy prototype of Dr. Mario was found at an internal development studio responsible for making official Nintendo strategy guides. Virus, a very early version of Dr. Mario for the Nintendo Entertainment System, happened to be discovered at this same location.

Not to be confused with ALF’s home planet, Meldac was the name of a Japanese game developer best known for the highly bizarre Nintendo Entertainment System shooter Zombie Nation.

  

 on the front of the cartridge refers to Heiankyo Alien, a Game Boy action game developed by Meldac, which was released stateside in April 1990. Dr. Mario debuted later that same year during the holiday season (link).

When this Nintendo studio received new titles, employees would remove and replace the EPROM chips and reuse cartridges, which would explain the strange pairing of these two unrelated games.

Unfortunately, that is the only thing strange about this Game Boy prototype, as its data matches the verified dump of the retail game.