Being one of the first FPS' to have a talking protagonist, it ads more depth in the character department and the gameplay is much fun as the levels are less linear, being that the levels are places you'd find in real life like a grocery store or a movie theatre and the nonlinearity results in the single player maps doubling as the multi-player, and the gameplay nothing short of addicting as I dont know how to mod but I really don't mind as multiple replays aren't boring as you WANT to find more secrets and refrences, SO YES, YES IT'S TOTALLY WORTH THE COST GO GET IT NOW!!!!!!!!!!!!!