Are there any hardcore/adult games for the Nintendo Wii?

Besides the Conduit and Mad World, probably not.

There's Deadly Creatures, not really "hardcore" but it's more of an adult game. You play a spider and scorpion.

Why not get an Xbox 360 or PS3, they have plenty of non kid games.

There are not many for the Wii, Mad World looks to be the best one coming out.