According to ESRB, this game contains: Blood, Mild Violence
Parents should know that the only blood and violence in the game, and that to which the ESRB rating refers, is when the player finds themselves in the firing line of a sentry gun. The only hands-on violent act the player themselves can perform is, hilariously, to gently push over one of the sentry guns so it becomes inoperable. More subtle adult content can be found in the occasionally sinister and suggestive humour of robot narrator GLaDOS, but it is not explicit enough to warrant an ESRB warning. The thinking must have been that if you are mature enough to understand the joke, then you are old enough to have heard it.
While the game plugs into the Half-Life universe (and for that matter the great value Half-Life bundle The Orange Box) enough for it to be essential for fans of Valve's legendary shooter series, the most fitting audience for the majority of Portal's gameplay seems to be those who enjoy stage-based puzzle games and lateral-thinking challenges. It is one of the few first-person titles that I would recommend to a gamer who is unfamiliar with the format, or unreceptive to the first-person shooter archetype. Although some control skill and speed is required later on, the vast majority of Portal can be enjoyed by thinking logically and methodically about how to overcome the problem in hand. And if that sounds boring, rest assured that the humour, flair, and satisfaction that come with progress make playing Portal an absolute dream.
Deaf and Hard of Hearing gamers will find Valve's well-respected subtitle support in full effect. The 'Closed Caption' option allows every incidental noise and sound effect to be transcribed onscreen (if sometimes unavoidably quickly), with colour-coding to aid comprehension.
