I created a guide that breaks down the basics of this achievement, and shows the path on screen not just Pac-mans current position.
Essentially all you really need to do is load up Level 1 and follow the path, if you can match the movements (not button presses) and timing you should be fine. By following this you should get all the Om Nom Nom Series Achievements:
All Ghosts - For the All Ghosts achievement you only need eat the first four ghosts, and you'll likely get this naturally during play anyway.
Om Nom Nom x2 - Eat all ghosts twice in the level
Om Nom Nom x3 - Eat all ghosts three times in the level
Om Nom Nom x4 - Eat all ghosts four times in the level
Om Nom Nom - Eat all ghosts four times in the level and eat both fruit that spawn
It will take a little practice and a lot of patience to match the timing!