Hmm I don't really see a landscape concept, per se. Just a building. Neat reference.
Will the screen scroll horizontally? You're using 1-point perspective here, which looks fine. If the screen scrolls staying in perspective may be difficult. You could even repeat your perspective grid, tiling it by mirroring it for each "tile", therefore giving your self infinite horizontal space if the game will scroll. Perhaps a gimmick like the old school Defender could even be employed for seamless repeating.
Just a weird thought for you. It's always nice to explore original things to use for games to make them stand out from the sea of other games