Gem Gem is a Japanese Game Boy title with a simple, evocative title. It's highly likely to be a puzzle or match-3 type of game, given the focus on the repeated word 'Gem'.  The gameplay probably involves matching or manipulating gems to score points or progress.  Information on the game's development and release date is limited and would require more extensive research of Japanese Game Boy game catalogs.  It's likely to be one of the many puzzle games which were popular on the Game Boy.

Gem Gem (Japan)

Gear Works (USA, Europe)