The worst Pokémon game since Box
So, you transfer your Pokémon from your DS copy of Pokémon Diamond and/or Pearl... and that's it? It seems so. True, you can watch your Pokémon interact and have your Miis wander among them, plus it's nice that the game seems to be a motivator for helping you find Pokémon you haven't got in the DS games as you are given tips for finding them.
However you can't find any missing Pokémon in this game and transfer them over to Diamond/Pearl. What's even worse is that you will lose your Pokémon from Diamond/Pearl when you transfer them, meaning that if you want them to return to your DS game you have to move them back again. It's an overblown storage system for Wii and it's pointless.
It's a shame as My Pokemon Ranch is one of the few big names on WiiWare but at 1,000 Wii Points we can't see anyone except completists bothering with this. Even then, they'd be very disappointed. But some rabid Pokémon fans might get something out of it. But I'm a rabid a Pokémon fan and I'm not sure.