0 A.D. https://play0ad.com/ is more similar to Age of Empires.

Not at all. That would be a game called 0ad.

More like Fire Emblem

More like Final Fantasy Tactics

think more hexbased, turnbased, terrain and dice roll mechanics with unit upgrades being extremely important.

More like Heroes of Might and Magic. It's a turn-based strategy game where battles take place on a hex grid map. It's got full campaigns, lots of factions and units, resources to gather... it's one of my favorite OSS projects. Wesnoth has been in active development forever and is a real labor of love, as well as a showcase of collaborative game development.

Not really. This game uses a turn-based combat system with a hex grid. It's more like Sid Meier's Civilization, but with a drastically simplified economy and a strong focus on battles. It also has a Tolkein-esque fantasy theme instead of a real-life history theme.

If that sounds at all interesting, I suggest giving it a shot.