In Fun 5 - 'You need bashers this time' - How is bashing through the 'netting' supposed to work? In the Windows version they seem to just stop bashing when there's nothing directly beneath them, and in Lemmix they seem to move down slightly whilst still bashing if there's nothing directly beneath them and then stop bashing shortly afterwards. Do they bash if there's something in front of them at any height, or is it only if there's something above a certain point?
Well, the exact way it works is something like this:
1) When lemming is at (x, y) with y being the pixel immediately underneath its feet (ie. the pixel lemming is standing on), immediately after carrying out the bash stroke, it checks only the four pixels (x+8, y-6), (x+9, y-6), (x+10, y-6), (x+11, y-6) for terrain, and only on every other stroke (1st, 3rd, ...)*. y-6 means 6 pixels up, and x+8 means 8 pixels horizontally away to whichever direction the lemming is facing. If at least one of the 4 pixels are terrain, then bashing continues after a short bit of moving forward, otherwise basher stops now and transitions to faller. It's of note that horizontally, DOS Lemming's bash stroke reaches up to x+7 horizontally, so essentially it is a check of having more terrain just immediately beyond what has been bashed.
2) The basher moves ahead 5 pixels horizontally before the next bash stroke. While moving ahead, whenever the ground drops by up to 2 pixels, lemming will simply drop with the terrain but otherwise continue on, otherwise it stops bashing and transitions to falling.
*more likely a bug in the programming rather than intentional behavior. Some versions like the Mac actually checks on every stroke as expected.So in short answer, whether they continue or stop bashing is based only on having terrain just immediately beyond the current end of the bash tunnel, and only at a specific height. Also there's a slight tolerance to dropping that will not interrupt the bashing.
I think the basic concept behind it is that the lemming has to be a little bit beneath ground level, or having a true wall ahead, to be able to continue to bash, ie., they decide it's a little ridiculous if you can do something like dig down merely 1 or 2 pixels on flat ground and then be able to bash on without stopping. That's not to say the actual algorithm will produce logical results in every case, but for the most part it produces reasonable behavior.
The netting terrain in Lemmings seems to be not quite dense enough to support continual bashing with the DOS algorithm, but even if it were dense enough, you would not expect a perfectly horizontal tunnel as a result either, due to the fall tolerance behavior.