Thanks to Obfuscate, I just got Sapphire in the mail today, and I played it some solo, and some 2-player with my 6-year-old and my 8-year-old. Playing solo, I got to the last stage on Easy mode. I definitely plan to play this some more in the very near future.
I have to say that Sapphire really is a good game, and I am well pleased with myself for getting an Arcade Card Duo so as to be able to play it.