Gears of War focuses more on the use of cover than running and gunning. Finding a nice bulletproof barricade to hide behind while you prepare your shot can mean the difference between victory and violent death.
Cooperation can get you everywhere. Instead of just charging forward, set up a choke point and let the enemy walk into your sights.
The enemy can take cover, too. Instead of the typical FPS meat grinder, Gears of War encourages actual firefights with maneuvering and outflanking.
These enemy troops might seem dangerous with their guns blazing, but they're out in the open and can be easily picked off with a few well-placed shots.
Creepy, skull-faced aliens with guns--the hallmark of good science fiction.
Violent sci-fi aliens can be stopped only by violent sci-fi space-marine-type people, and these men are up to the task.
If there's no cover, no backup, and no place to maneuver, it's fine to just fall back on the "keep shooting until it stops moving" tactic.
Raining bullets as suppression fire can keep an enemy pinned down, but in the end, you need only one shot to take him down.
Cramped corridors such as these are tricky in firefights. You have to be fast, accurate, and able to avoid getting shot.
You won't see them very often, but friendly air strikes can help turn the tide of a battle.