You know I start at least one post a month with a seemingly tangential zoology metaphor, and I'm afraid you just hit this month's. Because when I think about Age Of Mythology, I think of Gomphotherium. Why do I think of a weird, extinct elephant? Because it was a perfectly good 'phant, is why, and a definite improvement on previous iterations on the theme of "Big Grey Lads". But alas, its sister clades Elephas and Loxodonta enjoyed a combination of greater efficiency and better luck, and gave rise to the hose-nosed champions we know and love today. Similarly, Age Of Mythology was a perfectly good game, but it was a diversion from the standard formula of the Age Of... series, and as it turned out, it was the main branch that would end up surviving to the present day.
In Age Of Mythology, there were only three factions: the Greeks, the Norse and the Egyptians. And as the name of the game suggests, each enjoyed access not only to the standard Sword Bastards and such one might expect from history, but also honking great monsters of various kinds, from Leviathans at sea to Sphinxes, Cyclopses and all the rest you can think of. There were God Powers you could use as well, which were essentially magical spells to conjure special beastuses, or put area-of-effect stuff onto the map. It was all utterly bonkers, and completely different from the pattern set by AoE1 and AoE2.
And although I never played multiplayer AoM, I can say for sure the campaign was both really long, and utterly superb - one of the best RTS campaigns there is, if my warm memories of enjoying it are anything to go by. There was a wild, completely over-the-top story that nevertheless managed to be quite tightly plotted while mashing up three separate mythic traditions, and big set pieces in nearly every mission.
But while AoE2 got a direct sequel, and is now getting another in the form of Age Of Empires 4, Age of Mythology got an expansion in 2003, a collected Steam edition in 2014, and a new expansion in 2016 - but no AoM2. I suppose with AoE4 in the works, such a thing is now unlikely, but what a treat an unexpected return would be. It would be the Total War: Warhammer of the standard RTS genre, and I reckon that sounds like a pretty fine thing.