FAQ: The game: advanced

You can purchase permanent upgrades in the lobby, using your earned SP. This can unlock additional units or Strategy, or make a small improvement for your current units.

In the list you only see the upgrades you can afford at the moment, plus the required SP for the next cheapest upgrade.

You can see your purchased upgrades in the 'My upgrades' tab in the lobby and in the 'Game' menu when playing.