My ratings:
Graphics, Sound, Gameplay, and Lasting Appeal are out of 10.
The overall score is out of 100%.

IGN Ratings:
All categories are out of 10.

Gamepro Ratings:
All categories are out of 5 and there is no overall score.

Gamespot:
All categories are out of 10.

Extended Play:
There is only the overall score which is out of 5.

Rating Meanings:

90%-100%/9-10/5: Must buy. Almost perfect.

80%-89%/8-8.9/4.5: Excellent.

70%-79%/7-7.9/4: Good

60%-69%/6-6.9/3.5: Average. Nothing special.

50%-59%/5-5.9/3: Rent it first.

0%-40%/0-4.9/0-2.3: Don't waste your money.