We are talking about overall ratings right? And the readers get to choose and if they are not registered it counts only fo 1/4 or something like that. If thats what we are talking about, maybe it could be something like: Game Level, User Score, etc.... We could have something like this.
1: Not worth your time.
2: Bad
3: Pretty Bad
4: Not Very Good
5: Average
6: Pretty Good
7: Good
8: Very Good
9: A Must Play
10: Excellent.
Maybe 9and10 reversed or something? Maybe more sentance like, I dont know...