Got through a couple months on Classic Ironman, much further than I ever did before. Attrition started to take a toll, however. Lost my only good sniper to bad luck. He was at full health in full cover, and got nailed by a critical hit that killed him instantly. Got out of that mission okay, but in the next mission my top Support got critically wounded and was down for a while. As a result, I ended up going into my first terror mission with three lowly squaddies accompanying the my veteran heavy and assault. I did pretty well, clearing about 2/3 of the map without issues. I'd lost about 1/3 of the civilians, but few of those losses were anything I could have prevented. I started to move into a warehouse to save the last of them. moved into a small entry room with two closed doors, rescuing a civvy who was inside. I stationed my experienced assault and my backup support at the door, ready for a breach entry with another backup inside and the other two on overwatch outside. Before I could open the door, a zombie rose up from the ground on the same square as my vet assault and killed him in one blow before I even got a chance to react. I have no idea how the zombie got there; both doors to the room were closed when I entered and the civvy was alive, meaning no aliens had ever entered. I managed to dispatch the zombie, but two Chrysalids showed up in the middle of it right next to my men. I knew none of my men would survive at that range, so I charged everyone I could into as close range as possible to try and blast them all down before they got to move. I got one, but the second didn't go down. It took down my support, critically wounded. Unfortunately, the only med kit available to stabilize him was on his body, which mean I was screwed. Then two zombies appeared. I actually managed to kill them both with my remaining 3 men before the support bled out, but in the process lost another assault. After that, I aborted the campaign. I had three three vets left, but two were wounded and wouldn't be available for the next mission, meaning I'd have to go in with a veteran sniper and four rookies. I wasn't even going to bother trying to play like that.

So, I started a Normal Ironman game, and I've breezed through my first two months without a single loss taking the hardest missions thrown at me. It's startling how much a jump there is in difficulty between Normal and Classic. I wish there was an intermediate level.