They're mostly spread out all over the place, as my group had cobbled a bunch of options together as we got less new. ( So to find out myself (and to answer 'what expansion'), I'll enable them one by one and see what shows up that I recognize. I'm probably missing all sorts of features not specifically in the lobby menu, but then again I'm used to having everything on. If in doubt, leave options off until you think you're less new at the game, you certainly don't need to try everything at once
Generally, we used Random Moderate/Easier for both AI's & secondary-AIs, but thats up to you bunch of you want to lower it to just random easier or pick them yourself. 7/7 is the default of course, but theres nothing stopping you from playing on 5 or 6 instead to start. (below 5 things get rather silly, and the firepower of 7 players will just roll over the AI there.)
Complex ship types without Core Shied Generators (If you want a more directed game CSGs do help with that, personally I like not having to deal with them) is nice, but could be overwhelming. Try Normal types instead if it is. Turning off Dire Guardian Lairs would help too, for a group of new players.
Unit Cap LOW. It does give you less ships/turrets, but we had four people and the game would eventually start having trouble running smoothly for us without adjusting the performance profile down. You can play on normal caps in MP, but that just accelerates when the slowdown happens in my experience. (and seven players of per-planet turrets will wreck things
anyway, if laid out well and with enough energy to do it
)
AI Options (& plots):
Reveal Random AI types - Doesn't hurt to know which AI types showed up if they're randomized.
Resistance Fighters 10/10 - They don't show up that often (and not often at the right time you'd want), but they help, kinda. Below 10/10 we never saw them do anything of use, but we did see them get killed by the AI a lot. Of the other two base game minor factions, we never used either marauders or colony rebellions.
Auto AI progress: 0 every 0. Theres no point in this for newer people, and theres Spire Civilian Leaders for this with a positive side as well. Never bothered changing it.
Avoid Astro Trains. They range from 'really annoying' to 'evil', and don't get any better.
Exp 1 - Zenith Remnant
Among other things, this one added the Dyson Sphere, which is pretty cool. At 10/10 intensity it produces its dyson gatlings fairly frequently, and it will show up on one (and only one, unless cheats are allowed) planet when the game starts. If you kill the AI station on the planet, its gatlings become friendly, and will go off and shoot AI ships and a few specific kinds of non-AIP structures. They will also patrol through your systems at random if the dyson planet is connected to yours, similar to botnet-reclaimed zombie ships.
The Zenith Trader is also nice (lots of very expensive but useful structures you can place while they are in a particular system), but the AI can buy things from it as well.
Golems - Easy is good for trying them out, they can be nice to have. They're the first of the 'superweapons', since they're huge, can be hugely powerful, and have a lot of health. However they take a lot of metal to repair, require you take the planet (or at least build a command station so they're flipped to you) and you cannot replace them without cheating. Botnet Golem is a more special case (There is only one of it, and it only can kill ships that are not reclaim-immune), but otherwise the same applies.
Exp 2 - Children of Neinzul
The X map type is super chokepoint-friendly, but you can end up getting cramped pretty easily if you don't breakout into the center. Also is difficult to play Fallen Spire on due to hub distance requirements.
Roaming Enclaves can be interesting, but not for a whole team of new players, since its both friendly enclaves and AI-friendly ones who are not restricted to waves or threat. (Hybrids are also interesting and from here, but are not new player friendly.)
Exp 3 - Light of the Spire
This one adds Fallen Spire! You want it at 4/10 (or lower, or off), but it does nothing just by being enabled. It adds an alternate victory condition (along with some ships and some heavily defensive buildings, and journal entries), if you survive reaching it. Or you can just go partway in, get a couple extra spire frigates, and then play normally if you want.
As well, there are Spirecraft. These are similar but weaker than Golems, and built by mining spacial asteroids. They
can be replaced (and have to in some cases like the Martyr), but only if you have the right kind of asteroid left.
Also it adds the Vanilla AI type, the least special of all.
Exp 4 - Ancient Shadows
Champions! They are kinda complicated to explain, but pretty good. They respawn for free when they die, and have nebula challenges to go through. (or you can turn on Alt-Champ in the AI options and have their progression based on gaining Knowledge instead of going through the nebulas) Modular Starships. They also trigger the AI to occasionally send its own kind of champion ships (only of the lowest tier) after your HWs in an exogalactic strikeforce.
Clusters map types can be nice, you start in one and the rest of the map is split into chunks so you can say 'Lets go to that group next' instead of 'This way?' or 'Towards that particular CSG'
Exp 5 - Vengeance
This adds secondary AI types. They're pretty cool and can make interesting combos, or terrible combos.
Also adds Showdown Devices, which spawns four separate indestructible objects which by their power combined, create a second alternate victory condition if you both a. hold on to all of them and b. manage to survive the result. Like Fallen Spire, having this enabled does nothing by itself, so it doesn't hurt to leave on.
Exp 6 - Destroyer of Worlds
Nomad Planets and the Exodian Blade. Both can help end the game a bit differently, but a Nomad planet with an intact warp gate can be a pain in the butt with its linking to normal planets and wandering behind your frontline shenanigans. Also the AI
really does not like the Blade, so you better be prepared to punch the AI with it if you locate and support it.
