Knowing the limitation of the animation system in BGE, I would like to make a eyelid-system for a character. I made a system that works in Blender, but it has a constraint influence driven by a bone, something that doesn't work in Game Engine.
You can download the test file here: http://www.pasteall.org/blend/41543
When eye.anim is animated (by being rotated), the eyelid.deform is influenced (with a Action constraint) to be raised or lowered, to have a natural movement. But, when I close completly the eyelid by animating eyelid.anim, eyelid.deform mustn't be influenced by eye.anim.
Again, the system that is in the file does work in Blender, but not in Game Engine. This is because it uses a constraint influence driven by a bone. And something like this doesn't work in BGE (*). The only way to change an influence is by Python... but I won't do this only for the eyelids.
(*) I reported this some years ago (and, by mistake, again some hours agou), but it is not a bug but a known limitation of the game animation system.