This has happened twice now; if I torture and convert heroes during the course of the game, when I come to finish the level by killing or capturing the lord of the land, nothing happens.

I have tried killing him, converting him, what ever. It just acts as if there's something left to do.

Am I missing something? Is there a way to force a level to complete?

Once you complete a mission, it tells you to quit to the map.

You have to press the space bar after that.

Most levels requires to "kill" the lord of the land (he can die in the battle field, in your prison, become your minion, turn into a skeleton... etc) or destroy the hearth of the enemy (or enemies) dungeon. You can see if there´s other keepers in the "?" tab.

If you are in a special level (marked with "?" in the flag on the map), then you have to do something different, usually killing all the imps or getting to the end of the dungeon.

I know about pushing space; it just doesn't come up. I never hear "You have Conquered this Land", even though in one map I've mined literally every breakable block just to make sure there is no one hiding anywhere.

It seems to be a bit hit and miss though because I tried one of the levels again and accidentally converted a hero and at the end I actually got the whole "push space to exit this land" thing.

Apart from this hiccup I'm really loving this game, It's much easier than I remember it though (I think I was 7 or 8 the first time I played it though).

On which map(s) do you seem to be unable to finish the level?

It was level 5 and 9 I think. 9 sorted itself out somehow when I loaded a slightly earlier save. 5 I had to start again.

At the moment it's not a big problem; I'm just trying to finish levels without torturing anyone.