Ok, so after a (short) game there are a few thinks that bother me:

1.) The way I thought the ark worked was that it would colonize one planet at a time, when in fact it colonizes the entire system and your pop count is the same in every planet you are (technologically) able to colonize. This means that the Vodyani can be very strong early if you come across a system that has many colonizable planets. In my game the system neighbouring my home system had 5 habitable worlds. Of course due to the RNG nature of the galaxy generator this is unlikely to happen very often. This can cause balancing problems if you get a very bad start because POP growth is slow but it is offset by how the POP count of the ark indicates the POP of every planet in the system it is occupying. It's a cool idea but I feel it will be difficult to balance. Maybe have the ark gain up to like 10 POP to distribute between planets and make it possible for several arks to occupy a system?

2.) Enemy fleets would bypass my defences to invade DIRECTLY, causing me to lose the ark without a (space) fight. Don't know if this is working as intended, but i had a fleet of 4 ships guarding the system i had occupied with the ark, but a craver fleet just came in and immediately invaded. So I lose the ark immediately. Getting it back isnt difficult and not much of a setback since it saves all system improvements and (I think) POP count, but it is annoying and counterintuitive that my fleet wouldnt intercept them first.

3.) Can invade colonies but not outposts? So the only way I have of getting rid of an outpost is by syphoning essence until it goes away. This isn't usually a problem but imagine the following scenario: I lose the Ark to an enemy fleet in System A to Faction X. I can later defeat the fleet stationed there to reclaim the Ark but can't occupy it because Faction Z decided it wanted an outpost in that system. This means you can starve/kick the Vodyani out of a system very easily. Early on this can mean your death!

4.) Manpower. I know I have a cap on how much I can have, and I know how much I need for each ship. What I'd like to know is how I can earn more Manpower per turn.

Overall, I find this to be a very interesting, fun but difficult faction to play as, but it still feels like a kinda rough concept. Lorewise, I couldnt get very far into the story because I got stuck getting the ruins anomalies (couldnt find more than 4 out of the 5 needed to progress).

Looking forward to testing another faction soon. Good work so far :)

Vodyani have some major issues. 

The RNG factor is immense.
 You dont only need a System with many hospitable planets in the beginning you also need to start right beside a minor faction for example to be able to compete with the other races.