A well-known bug in M1A1 is that the exploration levels, particularly Pfhoraphobia, are harder to beat than in the original. In the M1 engine, you could complete an Exploration mission by just looking at all the "must be explored" polygons; in M2 (and therefore AO), you have to actually visit all of them, which can be frustrating when you don't know which ones they are. Could this be fixed by introducing an MML [?command] to use the old M1 rule, and possibly having it turned on by default for M1A1's specific Map file?
[- ptarmigan0@hotmail.com]
Aleph One 1.1 and later support M1's exploration as part of original Marathon compatibility. This exploration goal is not yet available for M2-format maps.