A pit in two-dimensional game can produce unwanted logic problems. It's lower than ground level so there should be support for third dimension. But sometimes there isn't and that's the problem in Kaduria. Let's say you push a boulder in the pit. That's easy. What happens if there is something in the pit already, like another boulder or a monster? They don't fit in the same pit, but there is no way to put the boulder on top of anything, because there isn't support for third dimension.
I guess it's time to add that support. I really tried to go with only two dimensions, but it's impossible with the level of complexity Kaduria has.