So I'm gonna leave my way-too-late feedback on these missions while I play them, I've tried the first 3 and here's my take on this
scg61 is borderline impossible but you might make it if you rush trough and kill the agent with alot of luck, not that fun imo.
scg62 is very interesting, the gunboats prove a challenge but I managed to take them out, this mission might have been impossible if the enemy didn't attack base early because then you can progress. Very fun mission with a little twist at the end when you can see trough some bumbs like the enemy stocking up troops without attacking.
scg63 is litteraly impossible, there's nothing you can do, needs quite some re-work, like if you could bring the 2 groups together somehow it would still have been challenging but this is just ridiculous - it's not possible to infiltrate the base and destroy the biolabs with what your get.
scg64 isn't actually that bad, it's unique and I like that it's so diverse to take on an army of dino's while also having a NOD base to destroy. A few bugs tho are that there's a shortcut into the big tiberium field that is bugged and most of the time you can't move anything trough it, they will just go forth and back in an endless circle, there's not really a proper way to lead the dino's into the enemy base so I took them out before I began on the base. And I haven't found a wintrigger!
scg65 I think this one largely works as it should, only thing I can think of is that when you find your base sometimes your reinforcements spawn at the westmost NOD outpost and they will get killed. I also don't really like the random 2 Apache's attacking your northmost asset (Guard Tower) but that's just me personally. For the rest, I liked this mission, it's a nice challenge having to take on the enemy with no Weapons Factory until you find the old base, but I didn't really need it anymore after that
scg66 I think this mission is pretty fine overall, AI doesn't do much tho but if you could get that working I think it's a challenging enough mission if you keep the conyard. Those gun turrets are very well placed and makes it very hard if you want to attack them with vehicles.
scg67 make sure you put a losetrigger if you destroy the temple or else you can't win anymore. I also had to manually control my harvesters trough the entire mission because of the placing of the tiberium fields, but for the rest I liked it.
scg68 god this mission looks good on XCC, but I can't do it, the attacking Orca's just make it too damn hard, combine that with the chopper landing with Chem Warriors even though they don't move, I'm gonna try this once more but just because it looks so good on paper. Umm... now that I played and established a base... How am I suposed to get to the base or other islands? Perhaps I could've ordered a Chinook Transport if I didn't destroy the helipad but there's no way you can take on the enemy with just infantry..
scg69 this mission will only become possible if you only have to take out the Harvesters and/or Refinery's.
scg70 tbh this must be a joke, the enemy attacks instantly and there is nothing you can do to prevent them from destroying your mobile HQ.
The wild-west missions are pretty funny, perhaps enemy can be set to attack the village in the first one.
Harvester hunting old version is also a decent little mission, I can't say there's much wrong with it in comparison to the new one
Hard landing is a good mission as well - hard in the beginning and fairly medium-ish for the rest. It could use a bit of polishing though; the beginning is indeed very hard and it's difficult to get tibirium at the start, but I think it's a good idea to let the enemy base produce units that attack after a set time needed for the player to set up a base. Perhaps let the base produce those Flamethrowers, Chem Warriors + Flame Tank instead of letting them spawn from outside the map as I think that'd be a better solution in this case. There's also a landing craft with some Grenadiers and Minigunners at the start that gets stuck for the rest of the game together with it's units. I think the Apache and the Orca that spawn sometimes are a keep tho, as they actually go to the enemy helipad to rearm and go to function as forward base defense instead of dropping ordinance and being useless from then on.
Freezing death II: fun short mission with 2 armies clashing, very easy 10000 score XD
La Suprise du Chef crashes the game about 10 minutes in...
Desert Fox: when playing on my resolution (1024x768) the right side of the map where you can't go is visibilly unfinished and I found no win or lose trigger, a lot of the missions here don't have a losetrigger btw but I don't see it as a huge problem because I'd kinda understand that anyways if I lost everything.
Dark Forest: nothing much to say here, looks to work great!
So this is my feedback on everything in here, I sure hope it helps you with polishing those missions o7