Hi! The most of the stuff is modular, but the PSX Mega Pack II for instance contains whole structures, most of which are enterable. You can use the showcase pictures as reference to put together the levels. If you have purchased the PSX Mega Pack II, I can send you the Blender source file of the scenes I've made for the showcase pictures, so you could use them as a more straight forward reference or export the whole scene into the game engine with some small tweaks.