Why research disappears after building is sold?
I genuinely don't get it, and can't recall any other game using this mechanics. I think it spoils the game a little, especially where maps don't have enough space to have 3 large buildings.. I don't see why I can't build a research building, do the research I want and just destroy it, making space for units or another research building? It is not like unit buildings where units are created continuously - that makes sense.
Also unrelated, but pls update the game icon on mobile to something more compelling.