We are specifically looking at mega evolutions, though, and omitting abilities, like primal reversion. The evolution feature first introduced in Pokemon X & amp Y allows Pokemon to assume an even more powerful form when a particular item is used on them.
Go for it, if you are a fan of evolution, as the name clearly suggests that what the game is about. Looking for a game that is fire red based and has evolutions for maximum numbers of pokemon, then here it is. Complete Walkthrough of Pokemon Mega Evolution GBA ROM Download: