There are some upgrades available for certain buildings, for example
-roofing, shop and lighting on Stadium and you can perform all 3 upgrades
-several radio stations for radio building and you can choose only 1 upgrade - there is a message that you can choose only 1 radio to be played, for example news or sport news
and there is a problem with a Mining Station - there are 3 upgrades available, there is no information that you can choose only 1 (so I think I can upgrade all 3 options), but when I upgrade a second option, I lose the first upgrade, so only 1 upgrade is possible for this building and the player has to choose what to upgrade.
I think that there should be an information (like in radio building) that you can choose only 1 upgrade so people won't lose money on upgrades.
You can choose only 1 radio station, previous radio station will be disabled
No info that your previous upgrade will be removed/disabled
