Wii U owners in Europe could only purchase 18+ rated games (like ZombiU) from 11PM until 3AM — a ridiculous setup no matter how you cut it. Because Nintendo is based in Germany, and because Germany wants to censor protect its children, Nintendo applied to rule to all of Europe.
Now there’s some good news. Nintendo has lifted the Wii U eShop restriction, which means you can purchase 18+ rated Wii U games on the eShop whenever you want. And even the Germans will get to buy 18+ games whenever they want. This is because Nintendo struck a deal with German censors at USK to get rid of the silly rule.