LINE 9-inch round pan with plastic wrap, with ends extending over side of pan. Beat Neufchatel and 1/4 cup sugar with mixer until blended. Add dry gelatin mix, zest and juice; mix well.
WHISK in COOL WHIP and mint; pour into prepared pan. Mix pretzel crumbs, remaining sugar and butter; sprinkle over gelatin mixture. Cover dessert with ends of plastic wrap; use to gently press crumb mixture into gelatin mixture.
FREEZE 3 hours or until firm. Invert dessert onto serving plate; remove pan and plastic wrap. Let dessert stand at room temperature 15 min. to soften slightly before cutting to serve.