Spin-off story to "Sonic Generations: Friendship is Timeless", taking place between chapters fifteen and sixteen during the train ride to Canterlot.

Everyone knows that Sonic, Tails, Spike, the Main Six, Shining Armor, and Princess Cadance set out for and arrived at Canterlot aboard the Friendship Express to find and stop the monster that had intertwined two worlds and their fates together, but what happened along the way? While Princess Celestia and Princess Luna went on ahead and prepared for their arrival, Equestria and Earth's heroes had to go through more adventures in order to get to Equestria's capital city. Now, the story of their lesser known adventures shall be told.

So climb aboard the Friendship Express, grab a seat, and get comfortable. It's going to be quite a ride.

Sonic Generations: Friendship is Timeless TV Tropes page can be found here.

I've seen this idea done before, but as a fan of Sonic and MLP: FiM, I wanted to give it a go myself.

This, basically, is the story of Sonic Generations, but crossed over with the MLP:FiM universe, with Spike and the Main Six taking the place of Classic Sonic and Classic Tails with other MLP characters also appearing (most aren't listed to prevent spoilers). Except for Green Hill, there will be different areas explored, as well as pony rivals and different era bosses. So while it will have its similarities to the console and 3DS versions of the actual game, it will definitely have its differences too.

Also, in case anyone was wondering, there will NOT be any shipping in this story. At the very least, no crossover shippings. No SonicxRD, TailsxTwilight, TailsxFluttershy, or anything like that. If there is any shipping at all, it will only be between characters from the same universe. And the only humans in this story are Dr. Eggman and the ones that appear in the "Sonic Unleashed" level.

A big thanks goes to bvge on Deviantart for creating the new logo on the cover art. It's a vast improvement over the old cover art.

The TV Tropes page can be found here.

NOTE: Due to the length of many of the chapters in this story, most of them have been broken up into smaller parts of roughly 10,000 words or less to make the story easier to read.

This is a fic based on the Time Loop Files, the format of which was first codified by Innortal on fanfiction.net.
Here's a brief guide.
The basic idea is, one character (the Anchor, usually the main character of a fictional setting) is looping back to the very first moments of their parent series every time either they die or some kind of time limit expires. They of course end up monumentally stir crazy given enough time.
Eventually others start to loop as well.
The reset is not always perfect. Sometimes a loop's history will be different to the "prime" loop, or canonical plot.
"Crossover" or "Fusion" loops also occur, randomly. These can involve the home loopers having a guest, or the anchor for one universe spending time in another, or replacements of one character by another.
Vacation Loops are where the Anchor (or others) decide/s "buck it" and lets off steam by doing whatever comes to mind. There's little or no attempt to maintain the original timeline.

In addition, and particularly more recently, it should be known that this story has a collaborative element to it - people may submit loop ideas or loops, ideally at the Spacebattles thread (a link to the current version of which is on the Trope page), and they may become included.

There's two page image options, thanks to Filraen - the current page image has been edited by the original creator from this work of theirs.. The other one is here:
http://hourglass-vectors.deviantart.com/art/MLP-Loops-466030169

(Based after Majora's mask) Link finds himself transported to the land of Equestria after saving the world once again, later on in his visit monsters begin appearing near Ponyville. So he must stop them as he finds a way to leave so he can continue his quest for Navi.