Are you sure you haven't been defeated? When exactly does game end?

Currently the victory condition for most levels is the destruction of Empire's Core. Defeat condition is the destruction of player's ( Green Color ) core. There's also camera clap effect so game won't end ''suddenly'' but the visual effect shall take place first. If you do experience problem in specific level, please let me know and I'll recheck the scripts.

Regarding AI, as I said before, unfortunately current scripting tools do not allow me to keep AI off the player's area. The demo system that I have made would in theory allow you to use Warbands for all rally flags for AI players ( like casting Warband 1 would cast AI 2's all rally flag at the same location ) and AI's attack / defend priority manipulations would make them less interested in messing with other player's dungeons. Sadly right now this system is not stable enough and thus was not implemented into campaign. It is stored in drafts on my end and will be introduced if devs fix WFTO editor. For now, as I suggested, make sure there's no gold on your end, this will make AI lose interest in your land and less likely to try mess it around.

Cool. I really like your maps/dungeons.

As for the levels with problems, there's probably nothing you can do about it, but here's what I've experienced:
• I played level 2 for about 5 hours before I saved it and went to bed. I and one other underlord were the last ones standing. The AI survived because it did not expand or attack AT ALL for the entire game, and I survived because I walled off my core and used teleport pads and ghost pots (whatever they're called. I can never remember the names of things outside of the game.) The next day I can't find the game to load; so, I try to play it again. I either can't load the level because of a fatal error, or I play (on simple) for a period of time (15 minutes the first time, 36 minutes the second) before Mendicaus says something about/like "make sure your minions have the minimum necessities" before the camera clap. I come back to play later and I see level 2 has been completed? mkay.
• Sooo... level 3. I play for about 15 minutes before the camera claps. This time Mendi' didn't say anything beforehand. The game just stops.

OK. I came back to it today. And each level I played ended prematurely and the next one was available. Something is triggering the WIN condition. The last level I played, Mendi' said, "You've completed an objective." before the screen clapped. I have no idea what he's talking about. Also, it said 3 of 4 crystals remained, but all 4 looked intact to me. Neither I nor any of the AIs had reached any of them.

Ok, I will recheck win condition for each level.

I'm currently investigating it. Script-wise, everything is correct, Victory / Defeat are tied to Core states and as such, they can't trigger until Empire or Human player are dead.

There's small chance something got glitched on your end. If it's so, I suggest you restart Steam itself and then try playing the level again.

Since you got the level unlocked already, it will remain so even if I will push an update. This means you can return to the level that ended pre-maturely at any time and try again. I'll post here if I find something on my end.

I've been playing through and I likewise was getting a false win - when any of the allies had destroyed one of the Core shards

Good series of levels utterly let down by impossible rival in Level 8. Unlimited enemy minions, shields on inhibitors, massively overgrown minions (seriously?) and unfairly punished for enjoying a longer and more strategic game over a hack-n-slash mindless one...

Shame.

If there is still an issue regarding ''false'' victory please let me know. There is a chance I could fix this, if the problem persists in latest versions.

Regarding the difficulty - as you know there are two modes for choice. If Standard is too difficult, you can try Simple instead. It does grant plenty of bonuses as well as free gold per second gain which will help building dungeon and defenses faster.

Ohai. Umm... I deleted these maps long ago. All I really remember is my AI "teammates" either being utterly useless, or sabotaging my defenses by digging my walls out. I don't remember there being many, if any, problems with your maps, per se, but I very much remember there being problems with the AI which would be out of your control.
Edit: I may reload your custom scenarios later. They're really good.

The thing with AI team mates sadly still remains out of my control. Devs didn't introduce any proper solution for that. From my tests, if you make sure there is no gold to dig on your land and allies have someone to fight, they will be distracted and won't annoy you so much.

The false victory could be caused by some of experimental features that were used during the creation of this campaign. Game received many updates with patches so I'm not sure if the issue is still there with this campaign, however I had such problem with one of my other maps I've been working on and the fix I applied there did seem to work. Thus if the issue persists in this campaign again, I will try applying the similar fix and see how it goes from there.

Your maps are always awesome! I'm sure I'll load 'em again, and I'll let you know if shenanigans persist.