Defend your base against incoming enemies from all sides. Your commandos have ability to call special orders, upgrade turrets and towers. Playing 'E'ndless level gets your score on the leaderboard.
Use the tower's new and unbelievably cool Super Activated Abilities to lay waste to the endless swarms of balloons. You'll need all the firepower you can get to combat the new Balloon types and new tracks with moving parts and tunnels.
Choose your antibiotics wisely to fight off the infections and save your patient. A fun way to relax and without you knowing it, you'll maybe even learn something useful.