SONIC HEROES RAINBOOM
So I spent weeks trying to get the yellow chaos emerald (only to give up, and let Hannibal Lecter and My Little Pony take Sonic Heroes's spot in my mind) and then realize you can hold the dash button down to go faster. In a sonic game where you have to collect the chaos emeralds, which are like a rainbow…
I haven't gotten to Last Story yet but I do know that Cream is the one who takes out the yellow Emerald, so the story will revolve around Team Rose's many attempts to get it.
Contains spoilers for the identity of the final boss.
Amy Rose, Cream the Rabbit, and Big the Cat raced through BINGO Highway. Big smashed a cage and got a key. They were careful to avoid getting hit, and destroyed all Eggman robots in their path, using Team Blast whenever they encountered many at once. Soon they reached the end of the level.
The key sent them to a Special Stage, which contained the yellow Chaos Emerald. They raced through a tunnel, collecting Power Spheres in order to boost. They began boosting as soon as they began getting power spheres, and did not encounter obstacles for about half the way.
Then, they ran into several clusters of mines. They avoided them as best they could, but in the process slowed down, and began losing the emerald as they avoided mines.
Then they reached a path of red power spheres, which quickly got them up to Level 3, and they began boosting as quickly as they could, but no matter how fast they ran, they couldn't catch up with the emerald, which reached the end.
"There's Eggman!" said Big. "We should make him give back Froggy!"
"I have a feeling we're going to need all the Chaos Emeralds," said Amy. "Besides, if I get this emerald for Sonic, he'll have to like me. Let's try this again."
"We'll have to go through BINGO Highway again with the key," said Cream.
So they went through Bingo Highway and reached the goal.
"Let's see…" said Amy. "The Chaos Emerald seems to speed up when we do the boost, so how about we get to Level 3 first and then use the speed boost? There won't be mines until about halfway there."
So they ran through, collecting power spheres, and when they were at maximum power, they used the boost and ran as fast as they could. They collected as many spheres as possible, but when they reached the mines, they ran on the side of the tunnel, and when they ran out of power, they slowed down, jumping down. The emerald was going as fast as ever. Team Rose got to the path of red power spheres, but by this time the emerald was uncatchable and soon reached the end.
"I'm not giving up!" said Amy. "Let's try a new plan. When we're in Power Formation, all of us are running side by side, and that way we can collect more spheres."
They got to the special stage again, by this time they were pro at BINGO Highway, and Big collected as many power spheres as he could. The instant they were at full power, they switched to Speed Formation and ran as fast as they could. This time Amy jumped over the mines when they reached them, however, this allowed the emerald to gain more ground.
The next time, they tried to avoid using the boost until after the mines. That didn't go so well.
Then they tried their first strategy again. No effect.
They tried each and every strategy they could think of a hundred times.
"WHAT'S TAKING YOU SO LONG?" said Eggman. "All the strongest robots of the Robot Storm are getting bored and running away! Some are even killing themselves in boredom! I only have weaker robots left now!"
After 230 tries, Amy was about ready to give up.
By this time, Team Chaotix was waiting in the forest for Team Rose to show up, and Team Sonic and Team Dark had already beaten Egg Emperor. Eggman – or rather Metal Sonic, disguised as Eggman – had sensed Team Sonic, Team Dark, and Team Chaotix's presence at the canyon, the castle, and the fortress, and figured that Team Rose would not stop attempting this futile quest and find his Robot Storm tower unguarded, so he left to face them in their respective battles, and after his defeat at each one – although he was able to absorb Sonic and Shadow's data – returned to BINGO Highway to wait for Team Rose.
"Look!" said Cream. "What's that? I've never seen anything like it before!"
Cream was pointing to a blue Pegasus pony with a rainbow mane and tail.
"Rainbow Dash to the rescue!" said the pony. She flew through BINGO Highway. She flew into a jellyfish robot to destroy it and kicked the cage with the key in it, shattering it.
With the key, she flew all the way over to the gold ring signaling the end of the level. She used the key to enter the special stage.
"Sonic Rainboom!" said Rainbow Dash, and she began accelerating, with a rainbow energy aura around her. The Chaos Emerald began moving faster, but found it was having a hard time keeping its distance from her.
Rainbow Dash was now moving at incredible speed. She had to move quickly around corners to avoid crashing into walls, and stayed in the middle of the tunnel to avoid mines.
Soon they reached the tunnel with the red power spheres. The yellow emerald was almost at the finish, but felt a terrible fear that this rainbow pony might just catch it…
Rainbow Dash was now moving at maximum speed, with the full force of the Sonic Rainboom. The emerald was inches away from the goal when Rainbow Dash caught it.
Reappearing at the end of BINGO Highway, Rainbow Dash held out the yellow emerald to Team Rose. "This what you were looking for?"
"You found it!" said Cream.
"How did you get it?" said Big.
"Sonic Rainboom!" said Rainbow Dash.
"Sonic?" said Amy. "What's Rainboom? Is that a new technique Sonic picked up?"
"Not Sonic the Hedgehog," said Rainbow Dash. "Sonic Rainboom! It's my most powerful technique. I've only really done it a few times, but even that pesky Chaos Emerald couldn't outrun me with Sonic Rainboom."
Rainbow Dash gave the emerald to Cream.
"Thank you, rainbow pony," said Cream.
Rainbow Dash flew off back toward Ponyville while Amy, Cream, and Big reached Eggman's tower.
Only weaker robots remained because half of the Robot Storm were dead or run off. Eggman had to wake the rest of them up to get them to go after Team Rose.
Team Rose was able to get the purple Chaos Emerald without much trouble at all. None compared to that stupid yellow emerald. Sonic got the blue emerald, Team Dark got the green and white emeralds, and Team Chaotix got the red and cyan emeralds. Sonic used them to turn into Super Sonic, and with Tails and Knuckles defeated Metal Sonic in his ultimate form, Metal Overlord.
Although Amy would continue to chase after Sonic, she would never forget that amazing rainbow pony that got them the unreachable Chaos Emerald.
THE END
In addition to the above mentioned, this is a shot at the difficulty in getting the Chaos Emerald, implying that it takes something like the Sonic Rainboom to get it, and that even then it's a close call