The Big Brain Academy made by Nintendo for its Nintendo DS handheld game console is very educational for my kids. It has different categories (Think, Analyze, Compute, Identify and Memorize) and every main category has three sub-categories to play on. I find every game challenging for my kids and they enjoy it playing against time.
As compared to other video games I encountered so far, this is probably one of the bests for my kids to deal with. They will practice here their mathematical expertise, their analysis and logic will really ponder and their memory will really put to its limit. My kids' brains, hands and eyes are really working and it is a big help at one point in their studies. Being challenge with the different games on hand plus playing against time are points where my kids wanted to repeat playing it to gain more correct answers but in a way help practice their reasoning, logic, alertness, speed and mathematical speed.
As a father, this video game is highly recommended for kids. They will learn a lot from it and they might be able to love how to be challenged.