In a 15x11x2-inch baking pan, combine the corn cereal, corn and rice cereal, pretzel sticks, and mixed nuts or pumpkin seeds.
In a small saucepan, heat butter or margarine, Worcestershire sauce, chili powder or barbecue spice, and garlic powder over low heat until butter melts. Drizzle over cereal mixture, tossing to coat.
Bake in a 300 degree F oven for 30 minutes, stirring once or twice. Add cheese-flavored snacks, tossing to mix. Spread on foil; cool. Store in an airtight container for up to 5 days. Makes about 11 cups (22 - 1/2-cup servings).