1 cup boiling water
1 (6 ounce) package lime-flavored Jell-O® mix
1/2 cup vodka
1/2 cup melon liqueur (such as Midori®)
Arrange 12 2-ounce plastic cups on a baking sheet.
Slowly pour boiling water over gelatin mix in a bowl while whisking. Continue whisking while streaming vodka and melon liqueur into the gelatin mixture. Pour mixture into plastic cups.
Refrigerate until set, 8 hours to overnight.