Epic Games delivers an epic game!
It is possible to say that the only flaw in this game is that it's too short. 5 acts and 30 chapters - which on Insane will take you a LONG time - just doesn't feel like enough for such an amazing game.
Right, that's the cons out of the way.
Let me start with the graphics - they are the first thing you notice, after all. Brilliant, to say the least, even on a standard definition TV. Unbelievable detail on buildings and characters, and plenty of gore!
Playing GOW revolves mainly around the use of cover, and there's no doubt that it's needed. On Casual and some parts of Hardcore, going Rambo can be forgiven. On Insane, no chance, you just get torn to pieces. You'll be lucky to lay down fire for more than about 5 seconds before the health gauge glows an ominous bright red letting you know you're getting creamed. There isn't much of a story to Gears, and even if there was you'd probably forget about it amongst all the shooting/chainsawing/Hammer of Dawn-ing you'll be doing. Although, what story there is goes some way to producing the atmosphere of the game - Fenix comes across as a rebel with a cause, and ain't nobody gonna get in his way.
Another aspect which contributes to the spooky yet military atmosphere of the game is the music. It fits perfectly with the mood of the chapter and on the darker levels, makes you more cautious in your movement.
And never was there a sound sweeter than your chainsaw slicing through Locust flesh.
I don't think much more can be said about Gears Of War. I'm giving it hard based on the fact that Insane is one of the toughest gaming challenges ever.
If you have a 360 and no Gears in your collection, you must be mad.