Brain Age: Concentration Training review. Classic Game Room presents a CGR Undertow review of Brain Age: Concentration Training for the Nintendo 3DS developed and published by Nintendo. Sprouting horns and presenting a host of new challenges with increased difficulty, Brain Age: Concentration Training is a greater challenge than ever before. It's a daily regimen designed to sharpen your memory, which could be at risk due to the increased digitization of our everyday lives! Get off Twitter and train your brain! This video review features video gameplay footage of Brain Age: Concentration Training for the Nintendo 3DS and audio commentary from Classic Game Room's Derek.