Hey guys! Sorry for not responding to this topic very often. This hack was essentially made with no knowledge of how hacking worked, I made all the sprites then used some tools to insert them into the ROM and edit some info.
Originally, I had attempted to make it so the data simply overwrote the existing sprites so it would be compatible, but this ended up causing a ton of problems, because many Pokemon Red sprites are larger than their Firered counterparts.
There has been a lot of inquiry into making this hack compatible with others. Frankly, I think that would be totally awesome. If someone else knows a way to only overwrite existing sprite data and wants to do it, you have FULL PERMISSION from me to do so. Furthermore, I give permission to do whatever you want with this ROM or the sprites used in it. If you want a game where the Pokemon look like this, go for it. If you want to use just one of them, that's fine too. This was made because I thought it would be fun to do, and I think they should go to use as much as possible.
As for the trade evolutions, they evolve by leveling up.
In addition to the reasons RichterSnipes said, the backsprites for this game just aren't as iconic or amusing. Revamping most of them just gave sort of vague monstery blobs, while most of the front sprites were nostalgic, hilarious, and sometimes actually cool.