One of the most mature games ever, HotD has constant violence, sex, and actually broke the world record for most swears in a game. Upgradable weapons are a nice addition, and playing co-op is always fun. However, most of the game is suprisingly easy compared to its arcade brethren. Even more so if you have a friend with you, which can suck a lot of the challenge and fun out of boss fights. Couple this with it's legnth of only a few hours, and it might be better to rent this, unless you like going back for better scores.