This is one of the harder trophies at first. However there's a trick to this trophy that changes the trophy from hard to medium difficulty.
(Optional step) You may need to play a normal game one time on easy difficulty. Then once you lose (force yourself or just play normal) follow the next step.
On the main screen choose, 1 player, and choose Novice and then play the game normally, you'll be the only player on the screen and the speed of the game should be FAR slower to the point where you can rack up 20k with out trying (versus in the normal game, 10-15k would be normal). Once you score that much, the trophy should pop with out you needing to lose.
If it does not, trying playing the normal game on easy once, and then choossing one player.