Nice to see this is still going and being improved. Thought I'd give some feedback.
Can't choose to pick up low/high lever creatures (very annoying and sometimes a problem).
Can't slap imps while they carry a prisoner forcing them to drop it (so possibly also while carrying some other things?).
Noticed a Mistress often attempting ranged attacks from slightly beyond her maximum range, causing no damage.
The Tooltip appears over the icons for creatures being held in the hand.
Captured a building type but it didn't become available to build.
There's were a few other things I noticed while recently playing but can't remember specifics so I guess they weren't to important or overly annoying.
Something that would be nice would be if the game supported extra levels being contained in their own folder within the "Levels" folder. It seems levels consist of various files with a number, this makes it a pain to remove an unwanted level and seems like a recipe for conflicts. Being able to put new levels in their own folder would avoid all that, or even better if one could simply place the level.zip files in there.
There's one other thing that would make a substantial difference, possibly the single largest improvement, if you could improve the framerate to 60FPS (or whatever the monitor is set to) without increasing the game speed it would be a massive improvement to the responsiveness and feel of the game. This would make the game feel worlds better, I remember using Basemod for Diablo 2 which basically did this there and the improvement is hard to describe.