A whole bunch of you sent this one in, but we wanted to do a bit of digging on it before we tossed it up. As some of you from a few months ago know, there were quite a few pony pokemon mod hacks in progress. This is by far the most complete one.
As one of the pre-readers pointed out, Rainbow Dash actually gains speed and health as the primaries, so it does look like each character is loosely based on their attributes from the show. You can also check the chart up above out for the new elements. Gone are the water and fire types that we are used to.
The overall game is still Pokemon: Fire Red, but ponies guys... ponies.
Check out the wiki for more information, and a guide on how to try it yourself.