1. Graphics & Sound
2. Controls
3. Gameplay
So the game would get a magazine review rating of A,A,A (top in each). Hence, AAA.
Remember, it was coined at a time when those three factors were significant to a gaming experience. Not so much now, but still relevant enough.
I can't recall a gaming magazine that used a grading scale as described.
1. Graphics & Sound
2. Controls
3. Gameplay
So the game would get a magazine review rating of A,A,A (top in each). Hence, AAA.
Remember, it was coined at a time when those three factors were significant to a gaming experience. Not so much now, but still relevant enough.