Package files, with automatic conversion of. Rw4 (RenderWare 4) model and texture files (from OGRE3D XML format and DDS format respectively) with packages, making part creation possible for the first time. In 1.5 there will be (I think) 10 new parts (made by the creators of the mod) for the creature stage, all the Grox parts and all the hidden cell editor parts. Space stage overhaul (not sure what it is but I think it means that if you carry too much you move slow or something like that).
