Getting to wave 18 in survival is pretty easy with the 3 ninjas - 1 cat team. I killed almost nothing on wave 18, didn't let more than 2 critters get past me on waves 1-17 and got 33625 points, so I'm thinking that reaching wave 18 is enough.
Pfft, just got 172 yellow combo, all yellow shapes (I think) and no reds. Didn't get double points, already had all achievements, but the tick for the challenge was enough :P
Good game, a little sloppy on the controls, but hey, it's your first game (at least on kong). Good story, I liked the ending music. Greetings from Argentina ^^
 "SkullFace"){kind=icon}
 "Ubooly & Friends"){kind=icon}
 "They Took Our Candy"){kind=icon}
 "Elemental Balance"){kind=icon}
 "Papa's Taco Mia!"){kind=icon}
 "Asteroid Deluxe"){kind=icon}
 "Love"){kind=icon}
 "Castle Wars 2"){kind=icon}
 "Bunny Charm"){kind=icon}
 "Storm the House 3"){kind=icon}
 "Multitask"){kind=icon}
 "Music Catch 2"){kind=icon}
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 "Pandemic: American Swine"){kind=icon}
 "Splitter"){kind=icon}
 "Estamos Pensando"){kind=icon}