Graphics: 10
It's a normal NES game, you shouldn't have to expect anymore than that, nor any less.

Sound: 7
Like I said about the graphics, it's for the NES, but sometimes the sounds do get a little choppy, and irritating.

Addictiveness: 5
The sounds and controls make it hard to make this game for the NES addictive, but I can't really complain since this game did come out in the '80s

Story: N/A
There is no story, just like Most other Namco game, they don't provide a story, the game is to let you have fun.

Depth: 10
The game is really nice, if you really get into it, learn the patterns, and get through the game, you'll have yourself a keeper, every time you beat the game (if there is an ending), you can try and beat the high score you get by doing better.

Difficulty: 10
The game is nice, but the controls are hard to use, it's like the player's ship sometimes has a mind of its own and doesn't want to shoot or move, the difficulty increases in the game which is really nice, and I think it should stay

Well, it definitely qualifies in word count as a review, but there's more to one than just reaching that word count minimum.

For starters, you should really expand things, and try to assume that the person reading your review has never played the game before. After all, that's usually the reason people look to a review in the first place; it's to see what others think of it before getting it for themselves.

On that same note, don't assume that people know what a "normal" NES game is. Explain the pros and cons to the likes of graphics and sounds more instead of just writing it off as "typical for the console." There are many people who are unfamiliar with what the norm is for most consoles, especially the more retro ones.

On Addictiveness, why is it that the controls make it hard to be addictive? What of them was problematic? Simple does not mean faulty, so you should explain that well.

On Story, you're wrong. There are plenty of Namco games that have story. Even a lot of their arcade games have some story to follow. Just because the story was not explained within the game material itself doesn't mean that there is no story at all. While you are right specifically in Galaga's case (although you can still make an inference that it was just the standard alien invasion backstory), Namco is not devoid of story all the time in their games.

You really have to expand your explanations for your scores more before you post a full-fledged review of a game. Try to understand that not everyone will have just played the game as you have, and you may have to explain things in greater detail to get people to understand the good and bad that you see. And specify as much as you can, without going into too much superficial detail. Even if you just do that, it'll go a long way. Hopefully you'll come back with an even better review.