In a large mixing bowl, dissolve the red gelatin in the boiling water, stirring until completely dissolved.
If making the boozy version, add the vodka to the cold water and mix it with the gelatin mixture. For the family-friendly version, simply add the cold water.
Stir in the blueberries and diced strawberries into the gelatin mixture.
Pour the mixture evenly into clear plastic cups or small glass jars, filling each about three-quarters full.
Refrigerate the cups for at least 4 hours or until the gelatin is fully set.
Once set, top each cup with a dollop of whipped topping if desired, and garnish with additional fruit for a festive touch.