Prime World: Defenders is a tower defense game featuring collectible card game elements. As a player, you become part of a group of exiled treasure hunters that have entered the capital of an ancient empire where you get to fight off evil mutants who were the nasty result of some cataclysmic event. As you play, you can upgrade your magical cards plus earn additional cards after each battle. There are lots of battles where you can vanquish everything from small mutated fungi to powerful giant goblins and nagas. In addition to the story-driven single-player campaign there are missions with random elements for each session. There is also an endless game mode and new game plus.