In a large mixing bowl, combine the Jello and boiling water. Stir until the Jello is completely dissolved, which usually takes about 2 minutes.

Stir in the cold water until fully mixed.

Cover the bowl and refrigerate for about 2 hours or until it thickens and sets slightly.

Once the Jello has set, gently stir in the lemon-lime soda.

While the punch chills, prepare the ice.

Just before serving, mix the punch with the prepared ice.

Transfer the slushy punch into a large punch bowl or pitcher for serving.

For a finishing touch, consider adding fresh fruit slices or mint leaves as garnish.