Though the game's director "deliberately created Bayonetta from

Though the game's director "deliberately created Bayonetta from scratch" and has called its story "completely original", he has admitted using "some names from Scandinavian mythology" and playing "about half of" Devil May Cry 4 for research. As a fan of folk music, he named Bayonetta's set of four handguns after the old English ballad "Scarborough Fair", and its individual guns Parsley, Sage, Rosemary and Thyme. Hiroshi Yamaguchi focused on composing music for the game that has a "nice up-tempo beat" and expresses femininity through female choirs, pianos, and other "'beautiful' instruments"—though some tracks also use pure orchestra or folk instruments[—while Kenichiro Yoshimura transformed Shimazaki's Bayonetta design into a game model and used the digital sculpting tool ZBrush to create normal maps for its details Alice in the Country of Hearts
. He worked with Shimazaki on the model's makeup, referred to foreign models with similar bodies, and said "I really wanted to get Bayonetta's backside perfect. I guess I am into that sort of thing..." The language spoken by the Angels and for all Infernal Summons is Enochian.

To Kamiya, the core theme of the game and its protagonist's attacks is "sexiness".To "her femininity and sexuality", the developers made Bayonetta bleed rose petals instead of blood when hit, and used butterfly imagery as part of her moves and outfit.[35][36] Her giant boot, fist, and monster attacks reveal some of her body—her hair is magically formed into clothes but must be temporarily reallocated to forming offensive weapons—and when the player targets an enemy Anime Sverige
, red lips mark the enemy's chest; this led IGN to call the developing game a mix of "action and a great big helping of fan service".The game's sexual tone is reflected in its age rating in the United States: the Entertainment Software Rating Board rated the developing game "Mature" ("M", for ages 17 and older) for containing "Partial Nudity" and "Suggestive Themes", as well as "Blood and Gore, Intense Violence," and "Strong Language". (By comparison, Japan's Computer Entertainment Rating Organization rated the game "D", also for those ages; the British Board of Film Classification rated the game "15" for "strong language and bloody violence"; and it was rated "18" under the PEGI system used in the United Kingdom and other European countries for its use of violence and language.

At the 2009 Electronic Entertainment Expo (E3), Sega chose Penny Drake to model as Bayonetta after auditioning 100 women. The company then joined men's lifestyle website Maxim.com to run a contest to find women who looked like Bayonetta. The grand prize winner, Andrea Bonaccorso, announced on November 23, 2009, received an Xbox 360, a 50-inch plasma television, and a copy of the 360 version of the game. Sega hired Japanese pop singer MiChi to perform "Something Missing", written for a Bayonetta commercial. The commercial, which has since been shown on the game's official Japanese website, touts the game as "non-stop climax action and features a model dressed as Bayonetta with a lollipop Assassin's Creed Kostymer
. In the U.S. and the UK, commercials have featured La Roux's "In for the Kill".

Demos of Bayonetta were released on Xbox Live and PlayStation Network in Japan on October 8, 2009, and internationally on December 3, 2009. The full game was released on October 29, 2009, in Japan, and was later released in other regions in 2010: January 5 in North America, January 7 in Australia, and January 8 in Europe. An update for the PlayStation 3 version was released on January 28, allowing players to install the game on their hard drive, dramatically reducing load times.