I don't mind if the next game has good/evil, domination/destruction or something totally new as long as it doesn't involve individually capturing hundreds of villagers again. That was tedium for the sake of stretching out the playing time and nothing else, IMO.
I really liked that in the first game if you died you lose the minions with you but nothing else changes. Sure, you CAN restart the mission again, but it's optional, not forced. In the second game, you HAVE to restart the mission, which annoys the flip out of me.
End battle in the second game was the most tedious and annoying end battle I've ever played - including a couple that I can't finish! Challenging is one thing, but boring is something else. Throw in that 'one slip and you have to redo the entire multi-part borefest all over again' and we're not exactly talking about a game highlight, here.
the only time I went back to old maps in 2 was to collect treasure to upgrade my equipment, which was also boring. 'Do the temple run six times to get the gold for the new weapon' is not exactly my favourite thing.
Sure, the life force gathering in the first one means a ton of arena combat, which can certainly get tedious, but you can wait for close to the end to do that.
The thing I think both games got wrong is that they are, in essence, one long tutorial on what your minions do, followed by an end battle. I'd like more side quests, more areas to explore and things to do that are not 'Rescue Hive' or 'Kill Main Villain'. The first is a bit better at this, but still needed a few more areas not directly related to the main quest to make it feel like a world, IMO.
As for the second, I think it has a couple of severe clashes between aspects of the gameplay that need ironing out. Levelling up your critters and buying upgrades for them makes literally zero difference to their actual abilities. Their equipment can make a huge difference, but they can wear any equipment at any level.
Either the minion levelling has to go, or it has to do something that is actually useful. I don't care which.
And that 'your minions have a maximum distance they run to, then they will just stop' HAS to go! On one occasion, my Greens piled up right behind an eradicator instead of overwhelming and killing him! An entire army lost to bad programming. I was not at all happy about that!
I also wasn't keen when the mounts refused to leave their areas for no reason. Sometimes it's justified - wolves hate fire, etc - but mostly it isn't. And why can't I teleport them with the minions?
With all my criticism of two, though, there is a great deal I like about it. I just felt that with a few changes it could have been an enormously better game than it was.
A bigger and more open world could make the third game the best of the three, IMO. 1/4 of the game being the tuturial instead of 3/4+ of the game would allow a better chance to build up life force and other resources naturally, instead of forced farming.
Definitely do want to see a third Overlord game