Sorry, 
I just realised I posted this in the wrong spot.

A few things now I'm 6 playthroughs through the open-dev.
- Line of Sight: units requiring line of sight is not intuitive as to what counts as LoS when fighting a battle.

- Reinforcements: it is not intuitive how these units work. Particularly painful with armies on single-tile islands, each person deploys 1 unit over and over again forcing many tedious battles. Should perhaps have some way of deploying on water with land units. 

- Needs a way to quickly cancel a movement command both on strategic and in battle

- Science-to-Production balance needed (learning new techs way faster than cities can possibly keep up)

- God-to-Everything balance needed (buying out city improvements currently way too strong on all difficulty levels)

- Ending wars: not obvious what each empire is offering to end wars. not obvious what crisis resolution means. AI never proposes surrender (only white peace - not obvious what this does)

- The speed at which you can progress through the ages makes most early cultures pointless (regularly advanced to the next era before unlocking unique unit/building).
- Owing to the above mentioned science-to-production issue turtling is not a valid strategy.

I'm loving this game and will probably put ~1500 hours into it (current numbers for CIV V and VI), but needs some work to slow down the snowball (for player and AI), or maybe that's just my play style. Speed up production, slow down science (same balance problem CIV has always had).