Sonic: Rivals [PSP]

Sonic is that blue haired hedgehog who can run like crazy and likes to collect gold rings. The Sonic name is usually associated with the SEGA system name as thats where it started.

In this reincarnation of the original game, the players guide him trough 3D levels on a 2D axis, racing against an adversary that’s also a Sonic, but he’s always a bit different looking with different special moves.

Players start standing still at the beginning of the level and end standing still at the right end of the map. The goal is to navigate Sonic trough the level (left to right) as fas as possible, avoiding traps or falling off the bottom of the level and making use of various power ups and weapons/traps. Collecting gold rings adds to the final score but has no influence on Sonic’s performance during the race.

Powerups/attack moves can be picked up by jumping into a powerup icon/box. Powerup effects are specific to the type of Sonic that picks them up.

Blue Sonic will gain super speed
Red Sonic will punch the ground and daze the opponent no matter where he is
White Sonic will scramble the opponents inputs.. make you go left when you press right etc
Black Sonic will scramble your screen

Attacks include ice, fire, wind, electric shock, proximity mines but also punching/kicking the enemy.
Each attack has 2 moves, if the enemy is in front the attack is usually released towards the target in front, self guiding. If the enemy is behind the player then the attack is dropped behind the player as a trap, except for the fire attack, it turns into a shield/force field around the player.
Ice trap turns the player into an ice block, mine blows him up, electric shock trap is disguised as a golden ring with a faint purple haze around it and wind will just trap the player.
Movement trough the level is so fast that it’s almost impossible to notice player traps and avoiding them.
If you get close enough to the other player you can kick/punch him. It will make him fall over and stop and he will lose some rings which you can pick up while you’re jumping over him.

The Rules:
Move from point A (start) to point B (finish line) faster than the opponent.
Falling off the bottom edge of the screen will reset your position to a safe spot before the fall and cost you some time.
You may take advantage of attack moves and power ups at any time if you pick them up. You will lose your currently stored powerup/attack if you fall off the level/hit a level trap.
You have to overcome all the challenges within a level to make it to the end.

The System:

Elements	Attributes
2 players	human / computer controlled
	always available abilities
	general acquirable abilities
	Sonic type specific acquirable abilities
Attacks	picked up by a player, activated at any desired point, will follow the level’s path forward but wont avoid obstacles
	dropped from the player’s 1 item inventory if the player has been affected by a level-trap / fall off the bottom edge
Traps	player traps placed at any point, will activate when opponent touches it, will disable/affect him for a few seconds
	level traps come in form of mobile enemies which have to be jumped on – mario style, there are spikes, lava, oil pits
	bottom edge of level, costs time, resets the players position, strips any powerups/attacks, removes a number of gold rings from his inventory
Level	is the playing field and contains all the other elements
	has a start and finish line
	contains obstacles / challenges, boosters to help the player overcome certain obstacles
Internal Relationships
player to player	opponents, have to battle for the lead position
	can use any powerup/attack/trap to their advantage to reach the goal
attacks / traps to player	will stop the player for a time period, may affect other attributes such as ring count and stored powerup/attack
player to level	players use level design to advance, players also have to avoid / overcome level obstacles
level to player	provides player with paths to the end, powerups, boosters to make passage of certain level elements possible, obstacles, traps
Environment
	playing the game
	controlling the game device, PSP
	wireless network if 2 human players want to interact with the same game using their PSP’s
Interactions
	The players interact by trying to out-run each other, doing so requires to attack / defend the other’s position using player-launched traps/attacks.
	The players interact with the level by following one of sometimes many possible paths, avoiding inbuilt traps and sometimes performing a certain action to be able to proceed.

All the rules and possible interactions tie directly into the player’s objective, to win the race. None of them are there for no purpose or just to annoy players.

The AI that controls the NPC Sonic is sufficiently advanced to make him use all available moves and activities to win the race. However it is attached to the player by the ‘rubber band’ technique, making it possible for the player to catch him after encountering obstacles and traps that cost much time but it also makes it impossible to gain a significant lead on the enemy. He will slow down when you’re far behind and catch up quickly if you’re in front.

The player can often choose to place traps in strategic locations, such as right after a booster which would provide the player with the required speed to overcome a looping or jump over a wide gap. Being slowed down/stopped by the trap after encountering the booster will cost him much time because he has to return to the booster and attempt to overcome the obstacle again.
It is also a good strategic choice to save up a powerup or attack for the last strech, to freeze the enemy right before the finish line, making it possible for the attacking player to win.