Apropos of CSS grid learning games, had anyone here used Grid Critters[1] and want to share their experience? It looks pretty slick, but the price tag makes me

Apropos of CSS grid learning games, had anyone here used Grid Critters[1] and want to share their experience? It looks pretty slick, but the price tag makes me hesitate. [1] http://www.gridcritters.com http://www.gridcritters.com