Left 4 dead is an exciting and well-made first-person survival horror game. It's a great game, but concerned parents need o be aware of a few things. Firstly, the theme of the game itself. Left 4 dead is about 4 friends teaming up to survive a zombie virus outbreak that has transformed most of humanity into bloodthirsty, agressive fiends. These creatures are fairly grotesque, most looking like pale, gaunt humans with blood on them, while others sport gross mutations, such as a creature with pustules all over it's head and back, with a long tongue it uses to catch prey, and a big bloated zombie that explodes in a shower of blood when shot, which attracts other zombies. Thes and other monsters may freak out some kids, and even some adults. Secondly, this game is quite violent. You can blast of f zombie limbs, heads, etc. This is quite graphic. There is no violence against humans, just zombies and mutants. There is some occasional cursing, usually s*** and d***. I personally don't find the game too offensive, as you are not allowed to shoot fellow humans, but instead must help them to battle the undead. In short, an excellent game for teens, and maybe some Tweens, depending on what you want your children exposed to.