On top of your characters snowball throwing attack, each character has a special power that can be accessed by hitting Y when their "special meter" is filled. You fill this meter by using your thrown snowballs, so it would behoove you to actively participate in the defense of South Park. Each special attack adds a character-specific ability for a short period of time. For instance; Kenny's special knocks coins out of every enemy boosting your funds, Cartman unleashes his fury to damage every enemy on the screen, or Butters turns into a whirlwind to take out an entire wave of enemies.
These special attacks are important because the waves of enemies can become quite the challenge as you progress. You'll have to time your special attacks to coincide with the stronger, or faster enemy waves in order to survive the stage successfully. Also, keep in mind what each character does - if you find yourself stuck on a stage, it is incredibly helpful to switch to a character with a very different type of special attack. On the subject of challenges, the gap in difficulty levels for South Park: Let's Go Tower Defense Play! seems much wider than it should be. "Casual" is almost too easy, Yet "Normal" can be infuriating in some places, leaving even a great co-op team struggling to survive waves.
In both the single player and co-op play, you will unlock characters that you will be able to switch between in your "party." Up to 4 characters can be used at a time in the game. Tweak, Jimmy, and others join the original four boys as you beat certain levels - each bringing an additional unique power, and their own personal touch to the amusing tower defense game. You will also unlock video files as you face new enemies or play with a new character. These video files are short clips from the show detailing creatures or characters you've encountered during your tower defense adventure - just in case you missed the episode introducing them in the 14 years that South Park has been around.