In a large bowl, combine the cereal, crackers and pumpkin seeds. In a small saucepan, melt butter. Stir in the seasoned salt, Worcestershire sauce, garlic powder and pepper sauce. Drizzle over cereal mixture and toss to coat. , Spread into a greased 15x10x1-in. baking pan. Bake at 250° for 1 hour, stirring every 15 minutes. Cool completely on a wire rack. Transfer to a large bowl; stir in M&M's. Store in an airtight container.