Is lemmings possible in flash?

I’ve tried to make a lemmings footer and it’s almost perfectly finished (except a nice user panel and a few stats but I can do that on my own)

My big problem is that I deform the terrain and lemming bridges by pasting black movieclips into a movieclip that appears at a higher layer than the terrain movieclip. This means of course that bridges (in the terrain movieclip) cannot be then built over the movieclip with black holes in it.

This is a serious gameplay error and renders tactical use of bridges useless.

Does anyone have any non processor intensive solutions or alternatives? Or even suggestions?

(I.e I don’t want to paste bridges and holes into the same movieclip and then have EVERY lemming hittest EVERY hole and bridge component then comparing their depths to determine whether the bridge has a hole in it or not)

see for yourself how annoying my connundrum is

[swf=“http://www.geocities.com/janaspararto/lemmings.swf height=60 width=300”][/swf]