In an interview with Wired, Sega President and COO Mike Hayes said that the disappointing sales figures for Madworld is not necessarily only because it came out on the Wii. "Was it that people didn't like the art style? Or that people didn't like the way the game played through? It could be many things, which we're obviously researching," he offered.
It's difficult because it was a critically acclaimed title; it was extreme but good. The thing that we're saying is, Sega would be extremely arrogant to have a title that didn't do as well as we thought on a platform and then say, 'Those kinds of games don't sell on that platform.' I think if you take our slew of more mature games - House of the Dead Overkill did really well in Europe., and for some reason even though it's a big (intellectual property) it did less well in North America. So that's kind of like a win and a miss that's kind of come out neutral.
Hayes also disclosed that they do consider The Conduit to be a success, being that they shipped 30,000 units and sold through half of that number. And even when the Wii is taking a downturn in its sales figures, the title is still selling consistently.
In conclusion (of the issue on making mature games, not the interview), Sega will still continue to make mature games for the Wii market because:
[...] With an install base of some 34 million in Europe and America (maybe half of who don't own Xbox 360s and PS3s)... So even if you took half of those where they're not into those (core) games, you've still got 8 million consumers to go for. So I think the sheer scale of the Wii allows a shooter, or a mature game, to be a niche but a successful niche. And because the development costs can be less on Wii, that means you can sell less to be successful... We can take more risks on the Wii.
So there, "Absolutely. You'll see more games in that genre coming from us."
He also talked about the recently delayed Bayonetta, the economic recession and surviving it, and creating titles that will cater more to the Western gamers. You can check all of that out through the source link below.