After Sonic the Hedgehog (2006) tried to revive the Sonic Adventure formula and was met with negative critical reaction, Sega decided to take a step back and think more carefully about the next game in the franchise. Borrowing well-received elements from Sonic and the Secret Rings and Sonic Rush, Sonic Unleashed frequently shifts between a classic side-scrolling perspective and a behind-the-back 3D perspective in an attempt to provide the best of both worlds. In general, Sonic Unleashed features a tighter, much more narrowly focused design when it comes to Sonic's standard ''high speed'' gameplay.
Like Sonic Adventure and Sonic the Hedgehog, Unleashed is broken up between two specific modes: Towns and Action Stages. Towns advance the game's storyline and house NPC characters (which offer side missions or items to Sonic) and generally lead the player to access the next level (an Action Stage) via that town's "Gaia Gate". In the PS3/360 Sonic Unleashed, new stages are accessed by collecting Sun and Moon Medals hidden within stages and towns, whereas in Sonic Unleashed for PS2/Wii, Sun and Moon medals are awarded strictly by completing stages. In comparison to past Sonic games, the towns in Sonic Unleashed for PS3/360 are considerably more compact in size and generally can be navigated from end to end in a matter of seconds. However, the Gaia Gates in the PS3/360 Sonic Unleashed, while compact in size, can be immensely confusing to navigate while also being unclear in presenting the player with their next objective to progress through the game.
The Action/Town stage motif is further broken down by what time of day they're accessed. While the sun is out, players are given control of Sonic the Hedgehog, who is equipped with the ability to boost, drift, homing attack, leg stomp, wall kick, and quick-step (a strafing maneuver). Once the sun sets and day turns to night, Sonic transforms into The Werehog, a shaggy beast who uses his claws to attack enemies and long stretchy arms for platforming. After defeating a certain number of enemies and charging up enough energy, the Werehog can "Unleash", making him move faster and hit harder, in addition to being invincible.
In Sonic Unleashed for PS3/360, things like defeating enemies, eating food, and completing certain side missions will earn Sonic experience points that he can use to upgrade his abilities. For Sonic the Hedgehog, Speed and Ring Energy can be upgraded, and for the Werehog, Strength, Combat, Health, Shield, and Unleash can be upgraded, and although the Werehog starts the game with only a small handful of attacks, by upgrading the "Combat" ability, over 30 combo attacks in total can eventually become available for the player to choose from. (In Sonic Unleashed for PS2/Wii, the amount of combo attacks available is much fewer.)
Differences Between Versions
Although Sonic Unleashed was released across four platforms, the version for Nintendo Wii and Playstation 2 (which was developed by Dimps Corporation) is in fact an entirely separate game that draws heavily from the PlayStation 3 and Xbox 360 Sonic Unleashed. (which was developed by Sonic Team) Some of the differences between the two games include:
- Being two separate games, essentially all of the content in each game is not found in the other, this includes the daytime action stages and werehog stages. Although some of the stages in the Dimps version draw inspiration from the PS3 / 360 version and try to mimic certain environmental features, other stages are completely new.
- The Dimps version of Sonic Unleashed is the smaller of the two games. The continent of Mazuri doesn't have any action stages in this version (aside from a boss encounter) and the continent of Empire City doesn't exist at all in this version. The game's action stages are also shorter.
- Different game feel when playing as daytime Sonic -- Sonic controls more 'sluggishly' in the Dimps version and feels drastically heavier in comparison.
- Many of the Dr. Eggman bosses such as Egg Beetle travel much more slowly in the Dimps version, making their difficulty level much more manageable.
- Different boost mechanic for Sonic. In the Dimps version, boosting is done by pressing the boost button once rather than holding it down. Each time you press the boost button, an entire tank of boost energy is depleted, and the boost lasts for a few seconds or until Sonic touches a wall. Whereas in the Sonic Team version, you boost for long as you hold the button down, and are therefore able to use it in very short bursts.
- In the Dimps version, boosting into an enemy causes Sonic to freeze for a split second and may even cause him to spin-dash, whereas in the Sonic Team version, boosting through an enemy is the same as if there was no enemy there at all.
- Compared to the Sonic Team version, the Werehog has very small range of attacks and combos in the Dimps version.
- In the Sonic Team version, running as the Werehog is done by holding a button down, whereas in the Dimps version, it is done by double-tapping the control stick in the direction you want to run. The way Werehog handles when running is also different. In the Dimps version, Werehog slides along the ground when running, essentially causing him to drift if the player changes direction, making him hard to control, but also possible to run for long stretches at a time if the player is skilled enough. In the Sonic Team version, Werehog has poor cornering ability when running, essentially meaning that the player may have to stop running momentarily in order to run in a different direction.
- Aside from the more obvious graphics differences, the framerate in the Wii / PS2 Sonic Unleashed seems to be more or less locked at 30 frames per second, whereas the framerate in the PS3 / 360 Sonic Unleashed varies wildly.
- Whereas the towns in the PS3 / 360 Sonic Unleashed are navigated in 3D, they exist in the Wii / PS2 Sonic Unleashed strictly as menus, in the vein of a point and click adventure. Likewise the NPCs are represented by still pictures (which change pose and/or expression) rather than being 3D in-game character models.
- The Gaia Gates in the PS3 / 360 Sonic Unleashed are a unique area for each continent wherein all of the game's action stages and boss encounters are hidden. In the Wii / PS2 Sonic Unleashed, all Gaia Gates look largely the same regardless of continent, and are each comprised simply of a large indoor temple room with many doors to enter. Whereas the PS3 / 360 Sonic Unleashed Gaia Gates are totally different from each other in layout and appearance, the only non-aesthetic difference between the Gaia Gates on Wii / PS2 are the puzzle rooms they contain and, of course, what stages/bosses the doors lead to.
- The puzzle rooms found in the Gaia Gate temples are an addition exclusive to the Wii / PS2 Sonic Unleashed.
- When playing on Nintendo Wii, you have the option to use motion controls or Wii Classic controller. This is the only version of Sonic Unleashed that offers motion controls.
Lastly, in Sonic Team's Sonic Unleashed, the player is constantly blocked from proceeding through the game until they have found at least a certain amount of Sun medals and Moon medals. These medallions are hidden in places throughout all the game's areas (both in hubs and action stages) and their location is not revealed to the player through any sort of radar, map, or hint system. They also cannot be earned by performing well in the game. This is in contrast to the Wii / PS2 Sonic Unleashed, where medallions are earned simply by completing stages, attaining S-ranks in the Sonic daytime stages, and reaching time, ring, and score thresholds in the Werehog stages.
It seemed like another routine assault on Doctor Eggman's latest orbital space station: a showdown with a couple hundred robots, and a fight to the death with the Doctor himself in a giant mechanized suit of armor. As Sonic uses the Chaos Emeralds to transform in to Super Sonic to finish the job, Eggman flees the scene, retreating to his final stronghold.
When Super Sonic catches up with the fearful Doctor, Eggman suddenly slumps to his knees and pleads with the hedgehog to spare him. He swears to change, to reform and stop trying to take over the world. Sonic is a little taken aback at the whole situation; Eggman has never begged for mercy before. This was, unfortunately, exactly the reaction Doctor Eggman was looking for. Catching Sonic off guard, Eggman pushes a button mounted on a nearby console. Large metal prongs raise out of the floor, and suddenly, Super Sonic finds himself trapped inside of a force field. As the machine whirs to life, Sonic is paralyzed and the seven Chaos Emeralds are forcibly extracted from him, de-energizing his Super Sonic form. Laughing madly, Eggman pushes another button on the console, triggering his stronghold's true function: A massive laser cannon. With the magical power of the Chaos Emeralds at its disposal, the cannon fires directly at the planet below, piercing it straight to the core. As the planet shatters in to fragments from the force of the blow, a mysterious, ethereal creature raises from the depths. Luring Sonic here and releasing whatever was trapped inside the planet was part of Eggman's plan all along.
Sonic himself is not doing too good, though. Having never been forced out of Super Sonic like that before, his body transforms in a different way -- he grows massive claws, sharp teeth and long, shaggy hair. Just as he is able to gain his senses as to what is happening, Doctor Eggman gleefully ejects him out of the airlock to the ruined planet below, confident that he has finally won the day. As the transformed ''Werehog'', Sonic plummets toward the ground from space, thus beginning a new adventure to reunite the continents.
The game of Sonic Unleashed spans up to 9 distinct continents. But not all continents are available all of the time - frequently the player will have to return to locations at specific times of day in order to progress forward in the game. For example, while the player visits the continent of Adabat during the night as the Werehog, they do not return there as Sonic in the day time until some time later.
Each continent featured in Sonic Unleashed generally has one town hub, one Gaia Gate hub, one main daytime stage act, and up to 4 main nighttime Werehog stage acts. In addition to those, a continent can have one or more more boss encounter (as either Sonic or Werehog), and any number of optional mini-acts to complete. (In Sonic Unleashed for PS2 / Wii, these additional acts are sometimes as long as the main stage.)
Note that Sonic Unleashed for PS3 / 360 also includes two Tornado shooting stages, which do not take place on any continent.
- Stage Name: Windmill Isle
- Based on Mykonos, Greece
- Stage Name: Rooftop Run
- Based on France and Europe
(Note: The Mazuri continent does not have any action stages in Sonic Unleashed for PS2 / Wii. Rather, it only contains hubs, and a boss fight against Egg Beetle.)
- Stage Name: Savannah Citadel (aka Clay Castle)
- Based on Northern Africa
- Stage Name: Dragon Road
- Based on China
- Stage Name: Cool Edge
- Based on Alaska and the Arctic Circle
- Stage Name: Arid Sands
- Based on the ruins of Petra, located in Southeast Asia.
(Note: The Empire City continent only appears in Sonic Unleashed for PS3 / 360.)
- Stage Name: Skyscraper Scamper
- Based on New York City, USA
- Stage Name: Jungle Joyride
- Based on Thailand
- Stage Name: Crimson Carnival
Tomoya Ohtani, one of the soundtrack artists from Sonic the Hedgehog and Sonic Rush Adventure returns as lead composer on the soundtrack for this game along with Sonic musical veterans Kenichi Tokoi, Fumie Kumatani, Hideaki Kobayashi, Takahito Eguchi, and Mariko Nanba. Orchestrated tracks for the game were performed by the Tokyo Philharmonic Orchestra. The game contains two vocal tracks:
- "Endless Possibility" by Tomoya Ohtani, featuring vocals by Jaret Reddick of the band "Bowling for Soup".
- "Dear My Friend" by Mariko Nanba, performed by Brent Cash, with lyrics by Candie Y
Purported to be in development since 2005, Sonic Unleashed's "Hedgehog Engine" is a multi-purpose game engine developed by Sega as an alternative to engines like Unreal Engine 3, idTech5 and the Source Engine. At the time of its release, the Hedgehog Engine was most notable for two relatively cutting-edge features: the rapid speed in which it could load streamed texture data off of the disc, and its ability to render Global Illumination lighting data. Global Illumination lighting is the act of light reflecting off of colored surfaces and bathing the surrounding area in that color. For example, sunlight cast upon a green floor will tint the walls and ceiling a shade of green.
At the time of release, calculating pre-baked Global Illumination data for a single level in Sonic Unleashed would take a networked render farm of 100 computers an average of 2-3 days.
Night of the Werehog
Near the launch of Sonic Unleashed, Sega celebrated the launch of "Sega Sammy Visual Entertainment", an animation studio opened not only to create high-quality CGI for Sega games, but to produce feature-length movies. In addition to animating all of the CGI for Sonic Unleashed, Sega Sammy V.E. produced an 11 minute short film titled "SONIC: NIGHT OF THE WEREHOG". In it, Sonic and Chip are caught in a rainstorm and take shelter in what looks to be an old abandoned mansion.
Unknown to them, a trio of ghosts haunt its halls - two of the specters are armed with cameras and compete for the affection of a lady ghost by snapping photos of their victim's frightened expressions, which she finds amusing. Though Chip is easily scared and makes for easy pickings by the ghosts, as they move in and attempt to scare Sonic, the ghosts are surprised when the storm breaks to reveal a full moon - causing Sonic to transform in to the snarling Werehog. Undeterred, their efforts to humiliate Sonic eventually devolve in to a knock-down drag out fight for supremacy. The two photographer ghosts from Night of the Werehog actually make cameo appearances in Sonic Unleashed, in the side-missions "Tower Terror" and "Fright Fight". In 2010, "Sega Sammy Visual Entertainment" was renamed to "Marza Animation Planet", where they underwent their first feature-length movie project: a CGI adaptation of the anime "Space Pirate: Captain Harlock".
- Early builds of the game called all the levels their real-world equivalents. For example, Apotos was originally listed as "Mykonos, Greece".
- Though towns are physical locations you explore on-foot in Sonic Unleashed for the Xbox 360 and PlayStation 3, towns in Sonic Unleashed for Nintendo Wii and Playstation 2 are simply a series of static menu screens. The Gaia Gate entrance stages are also totally different in the Wii/PS2 game. Rather than being outdoor areas, they are instead indoor temple areas containing many sealed doors that lead to action stages, bosses, or puzzle rooms.
- The Japanese versions of Sonic Unleashed for PS3/360 is called "Sonic World Adventure". The versions are nearly identical, except for one change: Mazuri's level, "Savannah Citadel" is renamed to "Clay Castle".
- On the North American box for the Xbox 360 version of Sonic Unleashed, an icon is listed for "Leaderboards". Sonic Unleashed contains no leaderboards, and all other versions of the game replace this icon with one for "Content Download".
- The music for "Savannah Citadel" during the day is actually a remix of a tune from Sonic the Hedgehog on the Master System used during the credits sequence.
- Similarly, the main orchestral song titled "The World Adventure" contains numerous similarities to the music used for Angel Island Zone in Sonic the Hedgehog 3.
- In the "Town" for the final location in the game (Eggmanland), players can find and talk to three of Dr. Eggman's Guard Robots, the Model Numbers of which are references to various Sonic games throughout the years: EF-MD1991, EF-DC1998 and EF-XB2006. EF-MD1991 is a reference to the release of Sonic the Hedgehog on the Mega Drive in 1991, EF-DC1998 being a reference to the release of Sonic Adventure on the Sega Dreamcast in 1998, and EF-XB2006 referencing SONIC the Hedgehog on the Xbox 360/PS3 in 2006.
- Once players talk to the three Guard Robots in Eggmanland, their character profiles are added to the game's Encyclopedia. EF-XB2006's character profile describes him as "lacking real world experience", likely a reference to SONIC the Hedgehog (2006)'s extremely poor critical reception. In similar fashion, EF-DC1998's description says that he was "Once a model mainstay of the Egg Fighter Force" but he has grown tired of working and now plays hookie to avoid his duties. This is potentially a reference to the fact that, prior to Sonic Unleashed, most 3D Sonic games were heavily based off of the ground work established by Sonic Adventure in 1998.
- Though never visible for more than a couple seconds at a time, it would appear that Dr. Eggman keeps a Dreamcast by his side wherever he goes, as any time you're afforded the ability to peek inside of his Eggmobile, it's always sitting next to him. Viewing the image in HD, it would appear he also carries two games with him: A never-released Sega Dreamcast version of NiGHTS: Journey of Dreams and a game apparently titled "Eggman Adventure", most likely a parody of Sonic Adventure.