I really enjoyed the naval gameplay showed on the stream: with treasure fleets, piracy etc. However I feel like exploration age is decent at representing interactions with new world, but at the same time it abandons the continental aspect of medieval ages, especially due to the fact that legacy path literally forces you to explore terra incognito, and not your homeland. At least from what devs have shown to us.
For example such system would not cover the land spice trading which started within the Eurasia between India, Arabs and Europe, or medieval Silk Road across the Eurasia. And in this case I would like to see not only naval but also land treasure traders. Maybe they could be less efficient (To support naval expedition like Portugal did in this situation =D) but for sure beneficial in case you are not a naval empire. For the same reason I think that treasure resources spread should work similar way to civ 6, when you have a few contents on your homeland and each continent have it’s own set of unique resources, and you have to get ones far from you somehow. And same for distant lands. It would be symmetrical, so trading is equal for all players in all lands(would be especially important for MP, in case there are players that start on different lands), and it would allow to stay relevant in case you are land empire without huge naval power.
Same with military legacy path it again forces you to be a naval empire. Making mongol an exception isn’t the way, I think all civs should be able to progress this path through colonizing your own continent (example - Russian colonization of Siberia) or capturing the neighbors(same Mongols). For example all civs receive full points for distant land settlements and half on a homeland (except mongols for example that have full points for any towns or cities on their land).
Among other medieval aspects - Religion got simplified and I am not sure how I feel about it. It had a huge influence on medieval politics and culture. And each player having it’s own religion seems to be “just another set of bonuses for now”, and doesn’t contribute much to interactions between players, how it was in previous civs. Especially Civ IV for example: when civs with the same religion had better relationships, different religions affected trading, alliances and wars. Maybe stream didn’t show a full picture and it’s deeper, I don’t know.
Also culture highly relying on relics seems incomplete. Yes, the art was mostly religious, but it was more than some religious artifacts: paintings, sculptures, mosaics, architecture, texts - all of this is a big part of medieval culture on the humanity’s way to Renaissance . Probably it is now a part of civ-specific great people, than it is okay, I just didn’t see that from stream.
Overall I think that there are still plenty of work to do regarding this age, and I am sure it will be more complete on release or soon later, but for now it seems significantly less worked out than antiquity (which is already really good).