Impressing you is impossible Ha - Sizes differ a lot in every environment. Make sure the sizes of the rooms are believable and suitable. Also, there is next to no realism; which isn't all too bad since it's based on a zombie survival gametype. - You try to get details from props and overlays. The geometry itself is down-right boring. Work on that. - Very dull use of colour with the lightning. It looks doesn't look interesting, and the boring lighting accentuates that. - Unrealistic aspect in terms of thickness of objects, growth of plants and prop placement. You try to add detail using the same ways you've been using in almost all your maps. It's a brush based engine, make use of it!