In an extraordinary move, Nintendo issued a warning to parents that children under age 6 should not use the 3D features of its new gaming device, InformationWeek reports, and everyone else should take breaks from it every 30 minutes, Nintendo says. “The 3DS does not require special glasses to view three-dimensional images,” which is why it’s not just a matter of taking some glasses off. The 3DS hasn’t been rolled out to the US market yet, InformationWeek adds. It will be shown publicly for the first time at Nintendo World 2011 in Japan this month, and the console version – which will run around $300 – will hit Japanese store shelves at the end of February. “Nintendo has not announced a release date or pricing information for the United States, although earlier this week, GameStop said is now accepting preorders for the device,” according to InformationWeek.