It probably works out to that but because of typically sporadic use it adds up. Games (any, not just graphics-intesive ones) seem use battery life faster though. It does have great "stand-by" battery life though.
I use mine every day and it gets the full 10-11 hours most people are getting for non-gaming activities, somewhat less for gaming activities, and charges way faster than I can drain it (though I haven't tried this while gaming I suspect it'll still be true.)
Something is definitely wrong with your iPad, and you should take it into an Apple Store to have it checked out.