Sonic Rivals

Sonic Rivals is a game in the Sonic series, developed by Backbone Entertainment exclusively for the PlayStation Portable. This is the first Sonic game to be developed by a Canadian company, and the first to be released on the PSP. The game was also supervised by members of Sega Studio USA including Takashi Iizuka.

The gameplay featured in Sonic Rivals is mostly faithful to the classic Sonic games, but it features 2.5 style, which is a first for the Sonic series.

Playable Characters

 * Sonic the Hedgehog: Sonic's special ability is Sonic Boom, which gives him a great increase in speed for a short period of time, knocking away opponents if he makes contact with them.


 * Knuckles the Echidna: Knuckles' special ability is Hammer Punch, which stuns any rivals in a large radius, giving an opportunity to attack or overtake.


 * Shadow the Hedgehog: Shadow's special ability is Chaos Control, which slows any rival down at a high rate.


 * Silver the Hedgehog: Silver's special ability is ESP, it confuses the opponent mixing their controls around.


 * Metal Sonic: Metal Sonic's special ability will have the same effect of whatever the opponents ability is. (e.g. Silver against Metal Sonic means Metal Sonic's ability is ESP)

Supporting Characters
Miles "Tails" Prower: Upon journeying to Onyx Island with Sonic, Tails is turned into a card by Dr. Eggman's camera as proof to Sonic that he indeed has the power to do so. It is now up to Sonic to save both him, and Amy, who has also been turned into a card. He appears as a playable character in the sequel, Sonic Rivals 2.

Amy Rose: The first to be turned into a card after Eggman, Sonic and Tails' journey to Onyx Island to discover this shocking truth. After Tails himself gets turned into a card, Sonic sets out to save them both.

Rouge the Bat: After discovering the truth about "Dr. Eggman", Rouge goes missing, but it is later revealed that she was turned into a card. Shadow sets out to save Rouge while trying to figure out what she had discovered. She appears as a playable character in the sequel, Sonic Rivals 2.

Espio The Chameleon : A card of Sliver only to help him.

Dr. Eggman: Eggman, in fact, is not the troublemaker in this story. He is actually the victim. He was the first to be turned into a card by his doppelganger Eggman Nega before the main storyline actually occurs.

Eggman Nega: As it turns out, Eggman Nega is the main antagonist of the game, who hails from the future. Masquerading as Dr. Eggman in the past, he uses a special camera to turn everyone into cards on Onyx Island, an island he brought along with him from the future. His master plan is to change his destiny by turning the whole planet into a card that he can control.

Bosses

 * Egg Turtle - The boss of Forest Falls. Involves Eggman's robotic turtle rotating on the spot pinpointing a location before extending its head and tail to attack. During this, the player must attack the head before his rival does. The process is then repeated.


 * Egg Falcon - The boss of Colosseum Highway. The same type of circular stage as the Egg Turtle, the Egg Falcon will fly over the player lowering altitude when it drops bombs of ice or fire. The player must attack the cockpit during this phase before his rival does. The process is then repeated.


 * Egg Lynx - The boss of Crystal Mountain. Unlike the previous two bosses, this battle takes place on a semi-circular field. The egg lynx will rotate on the spot targeting players before pouncing on wherever it faces. Giving the player the opportunity to attack.


 * Egg Kong - The boss of Death Yard. A robot representing a gorilla's head which shoots various projectiles at the player. Also assisting Metal Sonic in the process of attacking the player. Unlike other bosses, the rival will not attack the boss, instead, he will try to stop you. After all the projectiles, Eggman's brain capsule will eject from the robot shooting an electric current across the field. Giving the player an opportunity to attack.


 * Egg Destroyer - The boss of Meteor Base. The final battle of the game takes place on board a large rocket, which you will have to fight your way through Metal Sonic and various other obstacles to get to Eggman/Eggman Nega's Capsule. This boss will take 8 hits instead of 6 like the previous bosses.

Enemies

 * Venoom - Spider-like creatures that appear in Forest Falls. Official concept art of the game confirms the name.


 * Vultur - Vulture-like bird robots that attack you throughout Colosseum Highway.


 * MonoClown - Jester robot that rolls on one large wheel and punches players in Sky Park.


 * Yetee - Giant mechanized ice bots that can be seen hunched over in Crystal Mountain. In-game loading screens confirms name.


 * Metal Hound - Dog robots that attack you throughout Death Yard.


 * Drill Worm - Worm robots that can use their mouths to drill holes in the ground. Found in Meteor Base. Official concept art of the game confirms the name.


 * Egg Pawn - Another one of Eggman's robots, first seen in Sonic Heroes, often appears throughout the various stages.


 * Flapper - The cannon shooting robot as seen in Sonic Heroes is seen throughout the stages once again, now equipped with homing missiles.

Unlockable Costumes
Collecting all of a character's cards will unlock outfits related to that character. For example, collecting all of Amy's cards unlocks a pink track suit that can be equipped into one of the rivals (although this appears to be missing in the final version of the game for some reason). Each character has a total of 3 unlockable costumes:


 * Sonic: Leather, Ice, Black Tie
 * Knuckles: Leather, Armor, Eggman
 * Shadow: Leather, Flame, 80's
 * Silver: Leather, Lightning, Christmas
 * Metal Sonic: Leather, Circuits, Jester

Each one of the costumes can be customizable and used for many  multiplayer events and many missions.

Features
The game features 7 power-ups attainable during gameplay, adding a revamped power-up system, including both offensive and defensive abilities. These include fire, ice, mine, illusion, wind, ring magnet and star. While the star power-up is character specific, all other powerups are consistent throughout. Single player consists of a Story Mode, in which each of the four playable characters have separate story lines, and must race each other to the finish line in each stage in order to thwart Doctor Eggman's various schemes. Multiplayer mode is played Adhoc, and players can customize their racers using collectible cards won in Single player, trade cards with friends, and wager cards on races. Boss battles at the end of levels require you to not only defeat the boss, but also prevent your opponents from defeating it before you. As a throwback, Badniks (which have not been seen since the 16-bit era) are featured as enemies, though some are similar to those of Sonic Heroes.

Gameplay
While keeping with traditional 2D side-scrolling platforming elements, Sonic Rivals features complete 3D graphics, allowing the perspective of the camera to change while passing certain obstacles.

Sonic Rivals consists of many different modes: Single Player Mode consists of Story Mode, Challenge Mode, and, Cup Circuit. Wireless Play Mode features multiplayer games and races whereby players can wager cards, or just race for fun. The game's loading screens will give you tips on using each character to your advantage when racing. Although it was assumed that a Boss Attack mode will be featured in the game, these challenges have been implemented into Challenge Mode, where the player is given a goal to complete, such as hitting your opponent a certain number of times during a race or battle.

Performing specific objectives throughout the game will give you collectible cards. Such tasks include getting a certain number of rings, hitting your rival a certain number of times and getting to the goal within a certain amount of time.

Courses
The game contains six zones, each with three respective acts, the third being a boss battle. The same source states on the Game Info page that there are 17 stages per character, with each stage featuring two acts and a boss, with the exception of Sky Park which does not feature a boss stage. The stage names are as follows:


 * Forest Falls - A strange forest with terrain somewhat resembling Green Hill on South Island.
 * Colosseum Highway - A desert with ancient and dilapidated roman-style structures.
 * Sky Park - A carnival level with bright psychedelic colors.
 * Crystal Mountain - A snowy level with many ice formations.
 * Death Yard - A mechanical waste factory with giant fans and other wrecking-style obstacles.
 * Meteor Base - Dr. Eggman's base in outer space, which is situated in the middle of an asteroid field. In this final level of the story modes, the player will be assisted through both levels by two characters.

Cards
Sonic Rivals features an extensive collectible card system that spans a total of 150 cards, featuring cameo appearances of robots, major characters, minor characters, boxarts, and items from past Sonic games such as Sonic Heroes, Sonic Adventure, Shadow the Hedgehog, and even dating back to the original Sonic the Hedgehog. The cards themselves are used to unlock secret costumes for the characters among other things. 

Reception
IGN rated the game a 7.4 out of 10, highlighting its replay value, its graphics, as well as its entertaining stages. GameSpot, which rated the game a 6.9 out of 10, said there was a good sense of speed and colorful graphics. On average, this game has received a 66.2% through 28 reviews, according to Game Rankings' official score. Game Informer gave it a 6.75 out of 10