Overall, this mod did it's job lore-wise quite well. Establishing early tech and having some unneeded, but lore-related research was nice. The only thing I could expand is T'Leth lore and maybe post-game screen (if it's possible) to bridge the events to Xcom Apocalypse (If I remember, it was canon that T'Leth destruction polluted whole atmoshpere of Earth). Also some more research on "ultimate alien" and "who are the Freaks" lore.
Early game:The start felt really nice, you're not forced to even fight with aliens first month or so. Felt refreshing kicking some cultist ass (who are weak but you're also weak on that stage, since you can't bring heavy armor to surface missions). Mutant missions are interesting as well, but they get old after a while. Hallucinoids underwater monsters mission was the toughest for me, since they "eat" AP ammunition for breakfast. Was solved via heavy spam of Magna-pack explosives.
Polyphs are bull***, no comments there. I feel the guy who told in this topic about his spawnpoint being surrounded by those. I suggest nerfing their reactions/blast radius/time units, something.
As soon as you get gauss, things start to heat up. I also disagree with the magnetic navigation requirement for ONE pistol/rifle/heavy/auto etc. For ships it makes sense indeed.
It just forces you to grind more weaker USO's for these, since not all USO's even have them on board.
Gauss autogun is a great idea, that was my weapon of choice until I got sonics, even then it was still useful. Cannot say same for Gauss sniper. Low ammo, not so high damage, high TU cost.
Mid game:I guess the mid game is when you start using PWT / alien sonics. Also when aliens are really starting to spam bases where they can (perhaps this will be changed in 2.15, I had my mid-game in earlier versions).
The idea of being unable to recreate any sonic weaponry is neat, but at the same time, playing well will net you a ton of their equipment anyway. That was when I suggested disassembly of sonic ammo (glad you added this as well). PWT and melee from vanilla were not changed. I'm not sure if it's for better or worse.
For PWT it's incredibly strong on non-lobsterman levels (those bastards can eat up to 3 blasts and still survive) enabling you to clear for example whole first colony middle-part. Making everyone else on the level panic
Perhaps, I should have enabled the "aliens pickup weapons" option, since I had easy time once I force level-wide panic.
Drills (vanilla melee) are still hilariously overpowered. Even more with the "alternate moving methods" option enabled. This made clearing even lobstermen colonies easy because you can just sprint to one when detected, couple hits and done.
I still found the chainsword quite useful however. While it's very uneffective TU-cost wise (you can do up to 10x more damage in same TU amount with drills), it's still invaluably useful because of wall-breaching capability. I believe there was a similar item in Openxcom mod "Fusion torch" which I also used all the time to breach UFO's.
Mid-late game:For me the Sonic manufacture research came way later because I had no MC and couldn't capture a biodrone. So it changed when Freaks arrived with their crabs (which starts from when you research the clone Chamber I believe). Freaks remind me of starspawn from Cthulhu mythos (perhaps that was the intention) but they aren't that intimidating still. Only the shielded ones can pose a real threat, while the other ones can die even from gauss easily. Hellcrabs can be stunned in 2 hits if lucky, but they have impressive hp/armor, so generally a fair unit.
Sonic auto and sniper were somewhat a disappoinment for me until I edited them a bit. Auto variant really needs a snapshot and a damage (or armor penetration) adjust. It's still possible that a lobsterman survives a 4-shot volley, which takes 50% of your TU anyway. Sniper variant is good due to armor-penetration, but still isn't always reliable.
Ammo count was really low, I found myself comfortable with 20 on Auto and 10 on sniper. You can just raise zrbite requirement together with ammo count for balancing.
Liked the upgraded aquatoids/gillmen as well, but for me they appeared more rarely than normal variants even in later stages. Jellymen are a quite nice addition as well.
Oh, and there wasn't a clear hint for Armored Gillman Technician I believe, or I missed it, but it's needed for mech-suits.
Speaking of mech-suits, I wasn't really impressed. Especially when my Ogre armor guy got one-shotted through his shield with full hp with sonic cannon. Their grenade launcher is great indeed, but the sonic ram has really short range. Coupled with heavily reduced TU on soldiers in such armor, it's becomes slow and ineffective. Haven't tested Cyclop variant though since I had the later research already done.
Question - the Ogre armor requires Triscene corpse. But it was the Cyclop variant with the "flamethrower" weapon from Triscene. Mistake or intentional?
Late game:The true late game comes when you get MC. It directly depends on mindworm missions though.
Once you get MC armor and MC Battlearmor, 3-5 MC-gifted or just skilled MC soldiers, the game is basically over. For aliens. Since MC doesn't need line of sight, you keep your MC soldiers in spawn ready for action and storm the front with normal soldiers + MC battlearmor ones. The MC radar on the MCBA is INSANE. A lot of examples on it's usage:
Spawn on alien colony pt2 - you can instantly detect some bastards below the elevators, MC them and start bringing destruction. In fact, I had couple of bases where I destroyed the Synomium in ONE turn via alien MC chain.
Spawn on alien barge - same stuff. It's tightly packed with aliens, so on first turn you can already do major damage.
Spawn on terror / UFO mission and you can already detect someone outside the sub. Then you don't even need to risk reaction fire by just MCing the hell out of them on first turn.
I get the idea with MC nerf (limiting it to only one armor, which is weak.), but it still doesn't make it any less powerful. Without LOS requirement, you don't need to bring your MC crew to battlezone, just keeping them in the sub is enough. Even the Energy requirement is not helping, since you can "medkit" your MC soldiers with stims.
The other late-game stuff is Ion tier tech. BIG disappointment. I expected it to somewhat replace the Humanmade sonic tech, but instead it's just Ion piercer with 100% armor penetration, but ONE shot and 2-square ammo size. No displacer variant. Not usable on surface. Most weapons are alien-made. For Ion I was expecting every weapon to have some sort of armor penetration (but Tech Tree doesn't show any), but it's useless against armored foes. Armored tasoth/lobstermen take almost no damage. Only the craft Ion cannon was somewhat decent, but it's only really useful with 100% bravery pilots, since otherwise the shields are gone earlier than you can fire. With 100% bravery though, I even had my Manta with shield down a Dreadnought completely unharmed (shield was still up).
Solitone is a completely different story. Amazing bombs, Ogre grenades and solitone charges with armor penetration, but I wish for some way to replicate Solitone Bombs for launcher. I really didn't recover much of them even in 2.15. Also a solitone upgrade to PWT would really spice things up, since it generally one-shots your soldiers even with base ammo anyway. But if Lobstermen start to fear PWT it's another story.
Also, on late game I still get mutant / cult missions once in a while. The cult ones should be gone since you researched their database (and it states that Interpol is now hunting them) since they are just fodder when you have armors / sonics.
Other stuff:
Armors - I appreciated the Bionic/Hybrid/Adv. Bionic tier. Regeneration is really nice. When you don't get 1-shot. Unfortunately, most armors have this problem. Only shielded variants have some sort of insurance against that. Oh, and Bionic armored soldiers cannot be healed I believe (it says "there's nobody there). Which becomes awkward once they get stunned - you just can't use a medkit to bring them back.
Craft (and their weapons) variety - nice on early-mid game, but in the end it all comes down to Deep Angel / Manta / Leviathan. Stingray for slower Large targets in some cases. Torpedoes - I generally preferred Dolphin ones, the other seemed not so useful. Nuclear torpedo is really fun though, when it hits despite it's miserable 30% accuracy.
Suggestion is to add some Sonic/Ion variants for late game, since once you get Oscillators, you don't even really need torpedoes, if enough Zrbite is provided.
General geoscape balance - the old "gauss cannon" profit schema is gone, but you can still do less lucrative Particle sensors / Medkits. Gets you 3-5 millions per month. Having 2-3 bases with workshops can make you forget about funding and infiltrations completely. I guess you can somewhat change this balance by increasing prices / lowering profits, etc. If that's the intention anyway.
Some stuff I really loved and hoping to see in the OpenXcom UFO defense mods (they probably came from UFO to this mod anyway) is Training Pools / Adv. Medkits / Adv Flares. Naval / Transmission Nexus is really great as well. Shields are incredibly useful (especially for expensive crafts) and for soldiers it works as insurance.
Could even use advanced smokes (since I ran out of storage space on first few months and couldn't buy smokes anymore
Stuff I never got:
Flamethrower (not even sure it's possible to obtain)
Underwater Cult missions.
Oct terrorists (the first and last few of them appeared only on T'Leth pt.2)
Otherwise I ended on 94% research.