Anyway, enough of the boring stuff, here's what you clicked the link for, screenshots:
As you can probably see in the screenshots, there are 3d floors, so this will use GZDoom, but will not require it. Without the 3d floors, the map is till very playable, though the routes you have to take will be different. It will be a very open ended map, with multiple paths in/through the base area, and at least two paths through the outdoor area planned. More details as it progresses, if I can be unlazy enough to do so.