The Welcome Window appears when you first install Core GameKit. It contains links to resources / tutorials / support and more. If you need to open it after you've disabled the auto-popup, it's on the Unity editor menu at
Windows -> Core GameKit -> Welcome Window.
- 2D Physics: Used for combat in Killable and Triggered Spawner V2 events based on 2D and other minor scripts.
- 3D Physics: Used for combat in Killable, and Triggered Spawner V2 events based on 3D and other minor scripts.
- Addressables: Enable Pool Boss to use Addressables as well as referenced prefabs.
- Master Audio: Used to enable Master Audio integration, so you can chose to play Sound Groups during dozens of CGK events. The full list of events is here, and documentation page for each script also lists the sounds for it.