THE launch of Nintendo’s new Wii U failed to address investor concerns that the firm is ceding ground in the so-called “console wars”, sending its shares tumbling to a five-year low. The Wii U, complete with a new touchscreen controller, is aimed at winning back hardcore gamers from rivals such as Microsoft’s Xbox. Nintendo shares closed down 5.7 per cent in Japan yesterday, hitting levels not seen since before the original Wii was launched.