Real world definition of "mature": Showing the mental, emotional, or physical characteristics associated with a fully developed person; involving serious thought.

Videogame definition of "mature":
Shits, tits and gibs.

What is adult? According to ratings boards and hand-wringing politicians, the only qualifications necessary are a bucket of blood, a stream of foul profanity and a parade of naughty lady parts. Ironically, the very things that are included to win over immature teenage boys.

The following games, however, define adult in a different way. They tackle challenging themes, explore intellectual ideas and deal with complex characters in complicated relationships. They add shades of grey to an otherwise black-and-white form of entertainment.

Should little kids play Mass Effect? No, but not because they might catch a glimpse of alien ass or learn how to digitally stimulate their “se”xbox, as the media would have you believe. The sci-fi epic simply wasn’t designed for children and, as such, deals with many issues that children wouldn’t understand.

Racism is addressed, as Shepard navigates a minefield of prejudice, intolerance and segregation between the game’s diverse species. Foreign policy is debated, too, with humanity’s brash and aggressive military actions earning both admiration and resentment across the universe. Parallels can even be drawn between the current economic crisis and Mass Effect’s main twist, both of which result from our choosing the path of willful ignorance and least resistance.

Morality, diplomacy, obedience, deception, death, love, and yes, sex – the list continues. Like the best episodes of Star Trek, Mass Effect is about far, far more than spaceships and laser guns.

Rockstar’s sandbox sagas are famous for being big. The cities are big. The missions are big. The casts of characters are big. Until recently, however, the ideas were not.

GTA IV changed everything. While Tommy Vercetti and Carl Johnson showcased the “American dream,” working from hoodlums to kingpins, Niko Bellic discovered that life in the West is often no better, no easier and no more ethical than war in the East. While his predecessors reveled in money, drugs and prostitutes, he found that material gains often require moral sacrifices. And while Vice City and San Andreas boiled down to basic revenge tales, GTA IV exposed how the pursuit of payback was slowly eating away at Niko’s soul.

Who knew the immigrant, so fresh off the boat, would come to understand our culture more insightfully than any protagonist before?

Some of the most mature games aren't even rated “Mature." Braid is legally appropriate for anyone over the age of 10, as the fairytale visuals, soothing music and bouncing pint-sized hero give the impression of an old-school Nintendo platformer. The subtext of this seemingly innocent quest, on the other hand, requires a bit of life experience to appreciate.
Just ask Soulja Boy.

In a kids’ game, for instance, the ability to time travel might nab an extra life or bop an extra enemy. In Braid, reversing the clock solves a series of mind-melting puzzles and, at the same time, symbolizes the haunting power of regret. If the protagonist could try everything over again - correct his past mistakes - would the Princess return? Would she ever have left? If he could slow down the world, or lead two lives at once, would that somehow help reclaim her?

We all wish we could erase our errors, or go back and try a different path in life, with the simple press of a button. Braid capitalizes on this universal longing and, without spoiling the end, also preys on it.