Hello dasnotme,
The Demo Project is part of the Bundle you'll purchase for Card Game Combat. It serves as a playable demo for how to use the plugin and provides a number of examples of playable cards that take advantage of the various features of the plugin.
If you would like to look at the features in action without purchasing the plugin, we recommend checking out the Tutorial Video Series linked on the Store Page. It goes through a number of the listed features and shows in-engine examples of how they can be used.
For finished examples of games that use our plugin check out this collection for games on Itch.io. There are also a few games on Steam such as Deckbuilder Fantasy and Ember's Love which use the plugin.
Hope that helps,
MythAtelier Team