In a large bowl, combine the popped popcorn and mini marshmallows. Mix well and set aside.

In a medium saucepan over medium heat, stir together the sugar, corn syrup, and butter until the mixture comes to a boil. Boil for 2 minutes, stirring constantly.

Remove from heat and stir in the salt and vanilla extract. Allow to cool for 1-2 minutes.

Pour the warm sugar mixture over the popcorn and marshmallows. Mix thoroughly until popcorn is evenly coated.

Scatter the M&Ms and mini chocolate chips over the coated popcorn. Gently stir or fold to distribute evenly.

Spread the mixture onto parchment-lined baking sheets or a large tray to cool and set. Let it cool completely before serving.