Bolster buildings to battle better!
Exploring new islands can occasionally reward you with Elder Logs which will allow you to upgrade the buildings of your main base. Upgrading buildings will unlock perks that become progressively better.
Elder Logs can be found as an explorable island zone which will first appear at level 5. Once these have been explored, the Elder Logs will be stored in the Artifact Storage, which can be opened by clicking on the pineapple shaped building.
Tapping on the Elder Logs in the Artifact building opens the upgrade menu with all available upgrades.
Buildings can also be upgraded when opening their context menu directly on the island.
In the Upgrade menu of each building, you can either tap Upgrade if you have the required amount of Elder Logs, or scroll through following upgrade levels. Tapping on the blue Info icon shows the improvements of each upgrade level.