So, let me get this straight: You only bought five games for your Wii, four of which were first-party Nintendo games and one of which sucks, and you're complaining that there's "no core games" for it? Maybe you should do a little research first, because there's a ton of good games that you're missing, and a ton more coming in the future.
Really, the only thing the Wii is missing at this point is sequels to already-established franchises - and that was never the point of the system in the first place.
If you're still not convinced, though, then don't let the door hit you on your way out.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
