From EEDAR, a comment about Wii games (my emphasis)...
EEDAR:
Core Games on Wii Continue To Struggle
No More Heroes 2: Desperate Struggle has scored top reviews averaging a 90 (out of 100) since its release. However, sales came less than 30,000 units for its first week (January 26, 2010 release). Given that the game is more targeted to the traditional core gamers (who tend to be more attached to the Xbox 360 and PS3) this is yet another sign that the Wii is a difficult device for third party publishers to succeed on with M Rated titles. Other titles that have failed to perform despite strong review scores on the Wii include Dead Space: Extraction (ERTS) and MadWorld (Sega). Of course, all three titles did have low marketing budgets, which is likely the wrong strategy to use when attempting to target the Wii consumer, even if you are targeting the core market.