They've gone at leaders/civilizations backward. If they wanted to be bold, they would have your Leaders die at the passing of ages, and have you choose a new one. That way, you're not banging stones together as Benjamin Franklin (instead of banging French cougars).
From what I've heard, they've given up on having Religious victory, and folded Religion into Tourism (making it a part of Cultural victory). I don't know about you, but suggesting that Religion is made-up and passive seems a bit curt. Perhaps this goes hand-in-hand with the removal of City-States and the reintroduction of Barbarian Cities (or the removal of Barbarians and expansion of City-States, I guess), bringing the series back towards Civilization 4.
Not being able to upgrade units sounds like it's going to make Military Victory impossible -- unless you switch to whichever Civilization has the best unique troop of the era, but even THEN you have to build up your army from scratch on a regular basis.
Ages are handled more-or-less the same as in Civilization 6: Rise and Fall, except that you appear to get bonuses even if you play badly... oh, and that these bonuses are WEIRD, ranging from free Civics/Tech, to free units, to free money, to free Population, to
either free settlements or an increase to your settlement cap.
If there is a settlement cap, then that will suck, killing/neutering Wide play and basically forcing everyone to play with the same sizes.
There are three tiers to settlements. Towns let you build typical tile improvements, Cities presumably let you build only the urban tile improvements, and the Capital builds "Quarters" (which are presumably "super-Districts"). Tile improvements appear to be built in the same manner as Civilization 6 Districts (and Civilization 7 Districts) -- that is, to say, without Builder units. Towns and Cities can both build Districts. I assume that a Town immediately evolves into a City if it has enough Population and gets an open slot for doing so -- which loops me back to the settlement cap concern, only this time for Tall.
The Age delineation and civilization choices from the trailers are embarrassing. Every single African civilization can become every single other African civilization. How do they show this? By having Egypt's default swap be Songhai. SONGHAI. An Empire that existed FOR ONLY 150 YEARS, only noteworthy because it's the only Medieval West African state whose entire existence was recorded in writing. Then there's Buganda (the default Modern pick only for African Exploration civilizations), an East African Kingdom that was hardly relevant at all for
its 150 YEARS of prominence, before it stopped existing in 1962. There should have been more ages than just Antiquity, Exploration, and Modern; saying Antiquity ends with the big boat is kinda ridiculous, as that makes the second age last only 200-400 years (less than a tenth as long as the previous age).
Your Leader is geared towards one age, with their bonuses only seeming to matter for that age; or maybe Hatshepsut was a bad pick for their gameplay trailer. There are two preferred picks for Antiquity for your Leader, but you can honestly choose ANY Civ for your Leader. Then there's a bottleneck when the Age of Exploration comes: your Leader has only a few preferred picks for Explration, your Antiquity Civilization unlocks one default pick, and certain thresholds such as the now-memed "three Horses for Mongolia" exist for "ahistorical" switches. Then all that bullshit gets thrown out the window for the Modern Age; there are a selection of Civs that are only pickable depending on what your Exploration Age Civ was, but most are available to everyone, and your Leader does not matter at all.
Rivers being roads is fine, I guess... Wait, actually it's not, because rivers flow only one way. I hope they don't fuck that up. Also we have fixed (no percentage) Building bonuses and Adjacency bonuses again, so hyper-focusing on terrain in the early game and building Wide once you get Currency is the only way to go again. It's a little funny, seeing how absolutely-tiny Buganda was.
Faith has been
COMPLETELY replaced with "Influence", which has a stupid-looking icon and pools up around as quickly as Gold, even at the start of the game. Pantheons still exist, though, and are now gotten immediately after you research Mysticism. On a similar note, the "Writing" technology now has tiers.
I heard that Multiplayer supports only five players for long games and eight players for short ones. Hopefully that's just people lying on Steam.
Don't get me STARTED on how they're handling fog-of-war. We might be losing Military Victory entirely. Oh, and when you buy a unit, you can now place it ANYWHERE within your borders; that's just fucking great, totally not dumb.
The game has motherfucking Paradox-Game Random Events.