Japanese - mUpgradeSpawnerText3

Default:

Select an upgrade of your choice. The upgrades have increasing costs so you might have to wait for workers to come home, or even save up for a while to afford the next upgrade.

Last translation:

施設のレベルアップにはクリスタルが必要なので、ワーカーに指示してクリスタルを集める必要があります。