Stormgate
It's like 90% StarCraft 2 and 10% Warcraft 3. The competitive RTS part is promising but it didn't show me anything new. Depending on the lore and campaign it may get more interesting, so far it's neutral.
Millennia
It starts very similarly to Civ 6 with even more kinds of resources. The current version of the UI seemed confusing and the poor performance (on linux) stopped me from finishing the demo.