Started two short-ish rounds (medium galaxy, normal difficulty).
First Round: as Terrans vs. Iconians, Drenin, YOR, Onyx, Torians.
The Good:
Got strat. ressources form scavanging for the first time.
Only technical issue I ran into was a missing description and name on some kind of thulium U.P. resolution.
Turned Earth into a hiveworld with 30 billion population, looks good to me. Made me use celecrity citizens for the first time. I felt I lacked the means to produce monsantium however. Galaxy creation can now be insanely favorable to players who have access to it. I think there should be a monsantium shipyard project, then I would say the food system is acceptable. I like it, I can see this going places.
Non ressource options for weapons. I can really see them have uses, once jamming and hp aren't superior to all other defenses anymore and you may have to counter with something, you don't have the ressources for.
The Not-so-Good:
I still pulled ahead a lot early in the game. I would point the finger yet again towards asteroid mines. Especially now, that population acquisition is not trivial, and that rushing a constructor is only ~700 bc, The use of asteroid mines is out of proportion compared to all other means. I would suggest putting the cost up to ~250 bc and make the AI go for them more aggressively. It really doesn't matter if you turn the AI into Sun-Tsu late game, if it has the economic capabilities of say current day mongolia facing china by midgame.
I would like to stress the point, that I like the importance of asteroid mines, because they give incenive to deal with pirates more aggressively and thus give value to early ship building. At the same time it opens up beneficial strategic options for pre-invasion wars.
I think the reduction of manufacturing/research hub bonusses from 1 to .3 is ok-ish relative to other respective improvements, but it makes them way weaker, than having cities now I think. I like the general style of having one hive city with most of your citizens and population on it, but at the moment it kinda renders manufacturing, economics and research improvements obsolete. This is because in order to optimize, you want to have your player uniques on the same planet as your citizens, but now cities are the better alternative to these uniques.
Second round as custom civ: Silicate prolific slavers.
Left the AI so far behind, it was ridiculous. Especially given, that my empire building strategy was filling up all planets I had with slave camps. Exclusively. This rendered them 20-40 billion population hive worlds. Since I had little to do in terms of investing in improvements, I trained more spies on my planets and geared my orbital production towards treasure hunting. I must have had 15 or so spies by turn 100 and enough bc to bribe all AIs and plunge my sector into a war of all against all (save for myself). The Torians eventually surrendered their colonies to me, which is ironic, given that my sopies sabotaged their population improvements and my bribe started their war with the Drengin, which caused their collapse in the first place. Guess what happened to the colonies? I abolished most of the infrastructure and built labor camps instead. Shouldn't the U.P. be able to outlaw an empire such as mine? Well, even if there was a resolution for this, I held a >60% majority in it.
Ok, I see you didn't get around to align racial abilities with the new population balance. I hope you will take a look on it before releasing 2.5.
The Bad:
Work Camps should really not get +1 population from adjacency. Period. The +1 Population without adjacency is allready incredibly powerful, because it is population unrestricted by ressources.I'm not sure what to suggest here, mabye add 1 food cost to work camps and 1 population distributed over its upgrades while removing the morale boost.
I haven't tested synthetic yet, but I am almost afraid to see what I can do with those. I think they will need pop restricting buildings like the matrices again.
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Hope this feedback is helpful.