It is glitched as long as you put 30 minutes matches and beat the match in less time. Planting bombs takes one minute with one bomb at Manor House stage. All you have to do is run up the stairs in the middle house, grab the bomb, and plant it at the other base. You will end up saving 29 minutes per game since the game automatically counts as 30 minutes. Rinse and repeat and gain 20 gamerscore in less time.