Released on the DS, it has gone on to sell over 250,000 copies in a week. To put that into perspective, that's about 15% of all DS owners and the best selling game on Sony's PSP, Need for Speed, has sold in its lifetime about 325,000 copies as of the end of July, according to Kotaku.
We can almost see the gears grinding into place inside the heads of marketing folks the world over as they mix successful virtual pets with successful handheld consoles, and we expect all kinds of virtual pet shenanigans to be hitting up just about every handheld format you can think of in the next few months. ยต