You did not describe carpal tunnel, you just described wrist strain or tendonitis. Carpal tunnel is caused by nerve damage to your median nerve, and symptoms are usually that your wrists become numb, and begin feeling like pins and needles and your wrists become weak due to the nerve damage so then your wrist cannot function properly, and become more clumsy and you begin dropping things. Just put some ice on them, or take an ibuprofen or wrap with an Ace bandage, so can heal the inflamed tendons/ligaments and/or muscles you probably just strained from overuse. Doubtful it would be carpal tunnel, as you didn't describe the symptoms, and you don't get nerve damage from one day of playing video games. Even if it was, you'd do the same thing to relieve the symptoms, although more severe carpal tunnel could require a release surgery, something they would never do for a tendonitis or wrist strain, but even if CT, that's not likely something you will need to worry about yet at your age.