In the other article I mentioned, that the good way for rating games is considering all its advantages and disadvantages, thinking about:
- graphics
- music
- sounds
- plot
- gameplay
- level of fun reached while playing
- unique/fun features
And taking the mean from these elements.
Let's take the game Neverball, an opensource marble game, as an example for rating:
The graphics are nice, they are just fine for such a game, we could give it 8/10.
The music and sounds are not special but also not annoying, a little above average, 6/10.
Plot isn't present in the game, we can skip this part.
Gameplay (how entertaining and fluent is playing this game) - just fine, relaxing, but sometimes can be also quite challenging: 7/10
Level of fun: It is not a super entertaining bestseller like Skyrim, but you can get sucked up by game for few hours. Let's give it 7/10
Unique/fun features: Nothing special, just fine but this is not what we expected from this game. 5/10
Mathematic average: 6.6/10, so we can give it a 7/10.
There is also another, easier way. Just think for a second or two, how much you liked the game. Then, think does it have any pros and cons that can influence the rating.
Example? Smokin' Guns, the western FPS. I liked this game very much because of general idea of the game (western film atmosphere! yeah!) and some cool, interesting features (stationary machine gun, throwing knives, throwing dynamite, train map). I was really excited about it, I could give it a 9/10! But wait. It is made on old Quake3 engine and sometimes it can be annoying in gameplay and running/jumping characters look, also causing some technical issues (sound in Linux). We need to lower the rating. 7/10.
Choose the way you prefer :)