Played, closed the game, came back a while later and ... all bought upgrades from that previous round had mysteriously vanished. That's one way to create a lo~ng playtime. :/
The partly german/partly english game (when German is your default profile language) is unnerving. I'd very much appreciate having a game in ONE Language. Plus: Starting over isn't possible, since I don't have a clue what to type in the confirmation window ... "Verlassen das Spiel" - aka "leaving the game", written in the window, isn't helping either.