Have to say this is one of the best ROM Hacks I've ever played, and maybe my favorite FireRed remake besides Ultra Violet. Having completed it I can say I had a blast all the way though, even if I got mildly frustrated at times when I ran into a brick wall.
In terms of difficulty, I can say it is the first ROM Hack to have pushed me to actually EV train my entire team but the tools to do so in a fast and easy manner were provided. Besides that there were a couple of resets in the endgame due to poor luck and bad leads, but that's natural in a challenge hack like this I think. The only thing I can say annoyed me was the extreme stinginess from most trainers. Having equipped the Amulet Coin as quickly as I could I still only had 4/6 pokemon 'perfected' by the time of the e4. I don't know if being forced to grind for Meowth nuggets is intentional as part of the challenge, but it was quite time consuming even with the Pokenav. Regardless, overall, I can say the hack is challenging but not unfair which is a tough balance to hit.
On the note of criticism there isn't much to say, the game is extremely polished all the way through, although personally I think Giovanni 2 might be a little too tough given the tools available at the time :P. Only real glitch I ran into is one after the end of the game which has already been addressed in version 2.1.
I had an extremely fun time and I thank you from the bottom of my heart for this awesome hack soupercell, good luck in your next project!