Graphics are simple by today's standard but charming in the classical Asian kawaii style. The instrumental music is repetitive but heavenly enough until you get fed up with it, I guess. Unlike most MMORPGs, it has separate classes for tradeskills; I am playing an Armorsmith in Heaven. I find the notion rather amusing. Also, I'd love to see Heaven as crowded as this place! Luckily, the tradeskill classes are not entirely defenseless. The robots used for harvesting can also defend themselves, and they upgrade slowly with use. That is to say, even if you only use them for gathering resources, their fighting skill levels up in a certain proportion to their gathering skills. You can also get gold and xp by actual fighting, but there are other classes better suited for it.
Even though the game is free, you can buy various nifty things from their website to use in the game. I probably won't do that, I rather enjoy rolling around in a barrel-shaped robot and harvesting resources at a leisurely pace. But there are some pretty amazing robots and pets and spells, and I bet some of those are pay stuff. At least that would make sense.
Anyway, it is free, it is cute and it runs on cheap laptops. If they had these when I had more time and less money, I would probably have stuck with it.