Yep, bought it two days ago. Started the show a year ago since I didn't think we would get the game, and I watched about 2 dozen episodes. Part of the reason for this was because I wanted a glimpse at how the game worked and its appeal. Neither question was really answered by this, but I did get some gems out of it:
Aaaanyway, we got it, and I got it. I like it, too. The battle system is intuitive and has a lot to it, the world is surprisingly fun to traverse and interact with, and the game never forgets that it's about youkai. One thing that I notice about a good number of monster-collecting games (Pokemon included) is that the monsters rarely function based on the information given about them. They have an identity, but it rarely links to the narrative or the game and can often just be flavor text that does little except hint at what moves they might learn or the like. In Youkai Watch, though, every youkai functions like the youkai they are. In battle, their abilities are almost solely related to what that youkai is renowned for. In the world (ie quests and the like), youkai use these same abilities to both help others and reek havok. I really like this because it makes them feel three-dimensional, especially since pretty much every youkai has a personality.
And I really like the attention to detail, too. When I played the demo, the first thing I noticed was that when you leave and enter your house, you take off and put on your shoes (respectively). Another cool thing that certainly had kids in mind is that there are very, very small sanctions for using a crosswalk when the light is red (the pedestrian light, not the streetlight) and using it when its green. Plus travel's pretty streamlined. That I know of, there's no fast-travel, but say you want to get out of a school area that has a big fence that you'd otherwise need to go around to leave. Well, in this case, there will be nearby poles to shorten said distance. Plus, ridges can be walked off so you don't have to backtrack on paths that realistically could just be climbed down. And it all feels really good.
So yeah, I'm liking this game a good deal. I'd definitely recommend it to those who are interested, so long as you can leave the aforementioned Pokemon bias behind with you (because these games are not all that similar). Funnily enough, though, Best Buy's running a promotion where you can buy Youkai Watch and get a 3DS Pokemon game half off.