After only a couple of days I have lost, here it is:
Both expansions, 120 planet, Realistic
Assassin [7 Diff], Starfleet Commander [7 Diff]no auto AI increase
Complex Ship Type, Epic combat, Low ship count
Mods: Schizophrentic, Reveal Random AI Types, No Wave Warning, Cross Planet Waves
Minor Factions: Zenith Devourer, Zenith Dyson Sphere, Zenith Traders, Neinzul Roaming Enclaves, Neinzul Rocketry Corps
Plots on both: Avenger, Hybrid Hives, Advanced Hybrids, Astro Trains
This was my first time playing with the Devourer and Dyson Sphere, and I had not touched the beta before hand, but I did experiment briefly before starting (btw: no guardians with starships off, makes for an easy(er) game, but that has nothing to do with this one). My goal was to achieve the 110 planet achievement by belligerently taking every planet I can get my hands on and weather the storm that comes. Sadly, I didn't get to a point of skipping planets if i could.
I chose the Zenith AutoBomb in the middle, I thought they would be fun to spam mid-game once I had enough resources. The AI started out with MLRS and Zenith Electric Bomber. It started bleak, and bounced lower.
The three planets next to my home world were easy to take without guardians on them, even a MK IV world was very easy to take just starting off, it felt like there was no resistance at all. Then the hybrids came. Turrets are of little use (they don't take down the modular forcefield well). I found that there was two good ways to take care of them: your entire fleet can destroy one in a few seconds (with moderate casualties); or one volley from a ship cap of MK 1-3 Seige Starships will take it out (again in a few seconds). I found myself frequently ferrying my Seige ship (with a transport) to each of my planets to stave off attacks and even then it didn't always work and I spent quite a while constantly rebuilding lost planets.
The next world offered little more challenge than the previous ones seeing that I was raid-sniping guardians/guard posts/anything else with the Seige ships. The problem was that the command station had 30 hybrid hives on it, which made me retreat more often (but I could count on the fact that none followed me through the wormhole unless they had already targeted the planet I was attacking from). After 3 hours of attacking them to get down to 5 or so I realize that there was more than just a few forcefields over the command station, there was nearly 30, too much for me to take right now so I reloaded a save to where the planet was neutered (except for the warp gate which was heavily shielded) and moved on. I noticed that there were a couple more planets with excess shielding (more than just the 3 near my planets).
The next 2 planets went smoothly, some loss but I rebuild again. In attacking my 7th planet to be a cross planet wave erupted... but didn't, it stayed at 900+ [AI progress 150] threat and nothing happened, a roaming enclave showed up (not the first this game but significant later) but the wave never came. No other waves nor hybrid hives came neither, but I didn't noticed until later when I popped a command station with 170+ enemies still on the planet and no counter attack came, not only that I found an Astro Train not moving on the planet. I reloaded a save and prepared for the CPA.
It came in waves of 100 or so to one planet, my fleet was dwindling to the Zenith Bombers. My forces nearly gone (and not all of the threat were attacking yet) when the roaming enclave came (again). After some failure and reloading I had my Siege ships kill it just before it did any damage. Naturally, I celebrated at having turned a hopeless situation to have a smidge of hope. But there was still 70+ Zenith Bombers when they took the planet.
They conveniently went around my home planet and steamrolled over most of my other planets.
I realized now a few things I should have done differently, maybe that will make a difference. I shall restart from my first save (one second in, as always) and start again. Aside from the glitches, this map is win-able!
===My thoughts===
I still think the planets adjacent to your home world should still have guardians, even just the MK I variety. Its too easy starting off without them.
Seige Starships will take out any large threatening ship. The only thing it can't handle is swarms, which your fleet and turrets should take care of. They almost seem overpowered, they even easily out gun Bomber Starships that seem to be made for the same purpose. Why would you ever use Bomber Starships when you can use Seige Starships?
As my defeat has shown, I also think Zenith Electric Bombers are over powered in the hands of the AI. We get them in scarcely low numbers, they get them by the dozens easily, a few times 100+.
Turrets are quite incapable of dealing with Ultra-Heavy and Structural armor types, otherwise they seem to get the job done on the other kinds of ships: I almost never noticed or payed attention to a wave that came. It was like the waves were not important any more.
I dislike how hybrid have would load up on top of the command stations only on the planets next to mine, and they did this in the dozens. Hopping over would be very easy compared to taking adjacent planets but it would be much harder to defend later.