Phoenix Wright: Ace Attorney - Dual Destinies, to be released later this year, is the fifth game in the lawyer-adventure series – and the first to earn an M-for-Mature rating from the Entertainment Software Rating Board.

In fact, the ESRB has begun handing out more M ratings than ever before on Nintendo platforms, but that may reveal more about the board's process than it does about the actual content of the games.

A new trailer for Dual Destinies released today shows the Mature rating and describes the game as featuring "violence, blood, suggestive themes and language." This means that the ESRB recommends the game, a lighthearted comedic series of adventure puzzle games about a young defense attorney, only be played by those 17 and up.

The Ace Attorney series, which saw its first U.S. release on the Nintendo DS in 2005, often puts its protagonists in the middle of murder cases. But every previous game in the series has received a Teen rating from the ESRB, marking them as suitable for 13-year-olds on up. In fact, that first game was labeled as containing "violence, blood, suggestive themes and language" – the exact descriptors for the 3DS game.

It's possible that the content in the new game is somewhat more risqué than previous entries. In fact, Dual Destinies will also carry a more restrictive rating in Japan – it's the only game in the series to have that country's "C" rating (15 and up). It's rated for players 16 and up in Europe – again higher than any previous game.

But the rise in ratings on Nintendo 3DS isn't just limited to Dual Destinies.

So far, over 1,300 games have been released for the Nintendo DS since it hit the market in 2004. Of that staggering number of software titles, just 11 of them were rated Mature.

But the Nintendo 3DS, released just over two years ago, will soon cross that line – including Dual Destinies, there are already 12 Mature games available or about to be released on the 3DS.

All three of the Castlevania games on the original DS were rated "T" by the ESRB, but the 3DS sequel Castlevania: Lords of Shadow - Mirror of Fate, released in March, was M-rated. The ESRB called out "interactive sequences that allow players to stab creatures close-up (e.g., cutting off creatures' limbs/torsos; stabbing monsters in the eye)," and that "enemies emit splashes of blood when struck, and some enemies burst into pieces when killed."

The ESRB seemed equally hot and bothered by Mirror of Fate's more explicit sexual elements, writing this in its rating summary of the game: "During the course of the game, an extended sequence depicts a female vampire seducing a character while caressing a woman's thigh. A handful of creatures briefly appear topless in battle, and a male werewolve [sic] character appears to have an appendage/genatalia [sic] between its legs."

There's something to be learned about the ESRB here, and it's not just that the game industry's ratings board has no idea how to spell "werewolf" or "genitalia."

The 3DS games use 3-D visuals, not the hand-drawn 2-D art of their predecessors. None of the things mentioned in the ESRB description of the new Castlevania game are new elements to the franchise, but this time the sins are rendered in more vivid polygons, not more abstract pixels.

Speaking to TechCrunch in 2007, ESRB rep Eliot Mizrachi said that the "degree of graphic detail and realism has always been and will continue to be among the considerations taken into account by raters."

In other words, as creators take advantage of the additional processing power enabled by better machines to bring their visions to life in more detail, they run more risk of being labeled as adults-only entertainment.