Put the TV on the wall wherever you like to have it. Design carefully where you want to put the stickers around it. You can get a set of stickers really cheap on eBay (~20€).
IKEA Lack shelves match the green and add a little structure to the wall. Round the edges of the landscape stickers to give the impression of hovering tiles.
Some plush toys help adding some fun to the whole setup. Enjoy the next evenings playing Super Mario Bros in the perfect setting.