Complex sentence: Even in Japan, the game is widely unheard of, making it a very popular game amongst collectors, and the fact that it is the only game to use the Smart Media-ready cartridge makes it that much more sought after.
Split into simpler sentences: Even in Japan, the game is widely unheard of, making it a very popular game amongst collectors. And the fact that it is the only game to use the Smart Media-ready cartridge makes it that much more sought after.