A Game of Thrones is a total conversion mod for Crusader Kings II, based on George R. R. Martin’s fantasy novel series, A Song of Ice and Fire.
The mod feels quite stale and ultimately boring. The technical achievements are impressive, but the basic concept is quite lacking. It will satisfy your OCD, and need for a clean realm, but that will make it incredibly boring and not very challenging. It's fun to see the Game of Thrones setting in Crusader Kings II, but that's about the fun you'll get out of it.