Why don't you play something nice and happy?
http://www.nintendoworldreport.com/news/32745
Wii U games age rated 18+ can only be bought on the European eShop late at night.
According to an Italian NeoGAF user and confirmed by Eurogamer, the European eShop only allows the purchase of mature-oriented PEGI 18+ games between 11:00 pm and 3:00 am.
According to a Nintendo representative, this was done to "observ[e] carefully all the relevant regulations regarding content access that are present in the various European countries" and in order to "offer gameplay experiences suited to all ages." No specific regulations were mentioned.
Plan on accessing the eShop at night or buying a physical copy if you want to play or even access information on games like Zombi U and Assassin's Creed III. The games are blocked even when no parental controls are set on the console.