I greatly enjoy playing as the classic Alien (no way I'm calling it a drone), but it'd be something different to play as the Queen. A Queen campaign could be made challenging by it's very large size making it a easy target, and being frequently forced to crawl in small spaces. No wall climbing, and a much harder time finding places to hide.
One of it's sneak attacks could see the Queen brutally stab it's enemy with it's tail, and splitting them in two, like in Aliens. Imagine doing that to a human or a Predator.
Another one I just thought of is the Queen shoving it's tail up the enemy's ass, and slamming them on the ground repeatedly, before getting it's victim off it's tail.
A Queen campaign has just so much potential.