Sonic Unleashed went through many ideas and changes during the development process. What follows is a collection of items related to the game's development.
In the aftermath of the commercial and critical failure that was Sonic the Hedgehog (2006), Sega wasted no time in creating a successor that would not only make people forget about their previous effort, but also embrace the game series as they once did back during the Mega Drive days. Using not only the in-house Sonic Team, Sonic Unleashed gathered talent from the United States and Europe to assist with the Japan-based team to help reinvent the franchise. Initially intended to be the next installment in the Sonic Adventure series, the team decided to give the game its own identity, feeling that the style of game was far enough removed from what the pair of Adventure games had done.
Yoshihisa Hashimoto, the Director and Lead Game Designer of Sonic Unleashed stated that "the whole development team is aiming to make Sonic Unleashed the best Sonic game ever, and that includes the Genesis-era titles! We hope that even people who haven't played Sonic games will feel 'Wow, Sonic is back!'"
With that same mindset, Art Director Sachiko Kawamura looked at redesigning the Sonic character model, aiming to create the 'ideal' Sonic that fans around the world would recognize. Moving away from the lanky model of Sonic 2006, she tried to find a balance between the modern design of Sonic the Hedgehog and his classic appearance in the original titles. One of the many noticeable changes to the Sonic model was the placement of his mouth, which appeared on the side of his face when used in cutscenes to resemble the look of the original model art for the character, rather than the center as had become the norm in previous 3D games. As for the level designs, each was based on a real life locale, the idea being "what if Sonic were in the real world?" Even though its cues were taken from reality, the game still strove to be more cartoony than the previous effort.
It was also decided early on that Sonic the Hedgehog would be the only playable character in the game, so they could focus on the game mechanics for the hedgehog and not worry about numerous other characters and how they would control. This desire to illuminate what made the character of Sonic so appealing inspired the team to come up with the concept of the Werehog gameplay. Trying to think of a way to bring in players who had never touched a Sonic the Hedgehog game and let them experience the world of Sonic, it was decided this alternate playstyle would be implemented. Even though Yoshihisa Hashimoto knew from the get-go it might cause friction with the existing fanbase, he hoped that the fans would be open enough to understand why he would introduce this new form of Sonic, carefully designing Sonic the Werehog to appeal to both newcomers and avoid alienating the pre-existing fanbase.
Not wanting to leave the Wii out of this reinvention, Sega also contracted development group Dimps to help port the game to the Nintendo system as well as the PlayStation 2. Having been responsible for such titles as the Sonic Advance series and the two Sonic Rush games on the Nintendo DS, they seemed the perfect candidate to write up the code for the standard-definition version of the game. Instead of being a direct port, however, the level designs for the game were completely different between the two, the HD version released on the Xbox 360 and the PlayStation 3 becoming the one with more content.
The main theme song "Endless Possibility", was composed by Tomoya Ohtani and sung by Bowling For Soup's lead vocalist, Jaret Reddick. The ending theme "Dear My Friend" was composed by Mariko Nanba and Takahito Eguchi and sung by Brent Cash.
Various designs of Chip.
Various designs of Chip surrounding Sonic the Hedgehog.
Concept art of Sonic the Werehog.
A collection of NPC sketches used in Shamar. From Gurihiro Studios.
A collection of various NPC sketches, including Wentos. From Gurihiro Studios.
The female ghost from Night of the Werehog. From Gurihiro Studios.
Concept art of Thunderball.
Concept art of Aero-Cannon.
Concept art of Mole Cannon.
Concept art of Interceptor.
Concept art of Aero-Chaser.
Concept art of Egg Launcher.
Concept art of Egg Fighter Spring.
Concept art of Egg Fighter Knight.
Concept art of Egg Fighter Shield.
Concept art of Egg Shackles.
Concept art of Egg Blizzard.
Concept art of Egg Flame.
Concept art of Egg Typhoon.
Concept art of Spinner.
Concept art of Dark Bat Sniper.
Concept art of Dark Bat.
Concept art of Dark Bat Thunder.
Concept art of Killer Bee.
Concept art of Spike_(enemy).
Concept art of Dark Master.
Concept art of Fire Master.
Concept art of Lightning Master.
Concept art of Nightmare.
Concept art of Deep Nightmare.
Concept art of Big Mother.
Concept art of Rex.
Concept art of Dark Fright.
Concept art of Titan.
Concept art of Apotos.
Concept art of Windmill Isle. From Massive Black.
Concept art of Mazuri.
Concept art of Spagonia.
Concept art of Chun-nan.
Concept art of Holoska.
Concept art of Cool Edge.
Concept art of Arid Sands.
Concept art of Adabat.
Concept art of Jungle Joyride.
Concept art of Eggmanland.
A closer image of said breaking. From Massive Black.
Concept art of the planet post-breakup. From Massive Black.
Eggman's fleet. From Massive Black.
Dark Gaia breaking apart the world. From Massive Black.
Professor Pickle's study.
A collection of images of the people behind Sonic Unleashed working on the game, among other things.
Dark Gaia minions: