Is it OK to let my kid play Minecraft for hours?
An open-ended building game with seemingly endless possibilities, Minecraft can be mighty engrossing. On the plus side, Minecraft can reinforce geometry concepts as it strengthens players' thinking and reasoning skills, creativity, and even collaboration. The game has a strong, positive online community and even has an educational module teachers can modify for classroom lessons on different subjects. On the downside, as you've discovered, it's a time suck.
Even "good" games can be played to excess, and homework, chores, family obligations, and real-world social activities can take a backseat when kids can't -- or won't -- stop playing. And even if your kid is learning from the game, other areas of life are important, too.
Help your kids self-regulate. Start by having a conversation about all their daily duties and figure out how much game time fits in. Create a calendar, have them set a timer, and reward them for sticking to the time limits. If you've tried this and want more control over their screen time, consider installing a parental-control program that lets you set daily screen limits for different programs.