Combine sugar, flour and salt in a saucepan. Stir pineapple juice into beaten egg then into the sugar mixture. Cook over medium heat, stirring constantly, until thickened. Remove from heat and stir in lemon juice. Set aside to cool.
Cook Acini de Pepe in 3 quarts of boiling water for 6-8 minutes, stirring often. Drain and rinse.
Combine cooked sauce with cooked Acini de Pepe. Cover and chill in refrigerator.
When cool, stir in the well drained fruit, marshmallows and whipped topping. Chill at least one hour before serving. ENJOY!!