A engine I made, it's still a bit buggy. I am planning to make something like Wolfenstein 3D in Flash. I don't think Flash will be able to render a dynamic floor.
Edits: *V0.2 Fixed the perspective. *V0.3 Added the floor and more textures.
check this video out. [link] the main thing to know is .rotationX, ..Y, ..Z. So pretend a movieclip is a plane and then you can build things as basic rooms and boxes. Trying to do something like characters I don't see it with this method. There are no cameras so you have to move the whole container of your 3d scene.
[link]