We've added an auto-save feature that saves your progress after you have hit "H" to begin a "Defense" Round. You can load the save from the Main-Menu. The save gets deleted if you lose your current game. We are also working on fixing a few glitches in regards to upgrading fighters and bombers. Please report any bugs to support@corereactionstudios.com And any feedback to feedback@corereactionstudios.com Thanks for the support, Core Reaction Studios