Mash the avocados in a medium bowl with a fork, leaving them still a bit chunky. Fold in the tomatillos, mango, onion, chile, cilantro, and mint. Add the lemon juice, and gently mix to evenly distribute the ingredients. Season with salt.
Lay a piece of plastic wrap directly on the surface of the guacamole to discourage discoloring, and refrigerate until chilled, at least 1 hour. Serve with the chips for dipping.