Crystal Mines is part action and part strategy. There is a time limit to locate the crystals in each mine, plus avoiding falling rocks and monsters will keep you on your toes, but before long you will need to figure out how to locate crystals by properly removing obstructions and navigating tricky mazes. Crystal Mines was released as an unlicensed game for the Nintendo Entertainment System. Because Nintendo received no fees from the sells of Color Dreams titles, one of the largest unlicensed publishers, Nintendo threatened retailers by ceasing selling titles to participating retailers. As these retailers could not afford to lose Nintendo support, Color Dreams had a much more difficult time moving copies of their titles as a result.