I wrote this assuming you wanted a critical response, maybe you're not bothered about doing this as a career/hobby. I'm not an expert and I only read about a third of the text and skimmed the rest, but for what it's worth:
1. It's very formal in tone, although it breaks down in random places to something much less structured. Develop a tone and stick with it. It's not an essay but it's not IM either.
2. Compose paragraphs so you don't repeat yourself as much, try to make it flow.
3. Talk about yourself less, lose the repetition of "I am". You're talking about your opinion and preferences but it's about the game and describing what the reader will and won't like. Include yourself in places but don't bash the reader round the head with it.
4. First paragraph needs serious work, this is the attention grabber. Screw it up and you're lost. Work out your key points and trim the sentences down.
5. Read other reviews of Gears of War - what did they cover and how did they structure it? Learn from their success and their mistakes.
6. Keep writing!