There aren’t many player-facing changes in this update. Nevertheless, a large part of the game has been reworked. As part of these reworks, all your saved Mission Config presets have been reset, so you’ll need to save them again.

Summer content is still available, but you have to manually select it at the main menu via Options → Seasonal Content.

More information about this update can be found here: https://forum.chickeninvaders.com/t/ciu-version-147/33812