What's a good Android game for cooperative tower defense battles?

Rush Royale: Tower Defense TD provides a unique blend of tower defense and collectible card game mechanics, making it an excellent choice for cooperative battles. You can team up with friends to strategically defend against waves of enemies, combining your unique hero units and abilities to create powerful synergies. The game allows for real-time collaboration, where you can adapt your strategies based on your teammate's units and the incoming enemy waves. With a strong community and regular updates, Rush Royale offers a constantly evolving cooperative experience. The optional in-app purchases allow for faster progression, but the core gameplay is enjoyable without spending money, focusing on strategic unit placement and skillful merging to optimize your defense. Whether you have five minutes or five hours, Rush Royale provides fun and challenging experiences with friends.