To make it easier to get this and the other Score achievement under original mode, you should do the following adjustments in Game Settings:
Difficulty: Level 1
Bonus Rate: Every Bonus
Bonus: 10,000 / 20,000
And if you feel you need to be even more cautious: Numbers of Players: 9
By the time I beat the game in Original Mode: I got almost 700,000 and didn't use one continue.