This is a ridiculously fun little game that has the same simplicity and finesse of line-drawing games such as Flight Control, Harbor Master, and 33rd Division, which is a little more complex than the other two, but certainly as sophisticated. Not only will this gem appeal to fans of those games and games in that genre but also to any app collectors who enjoy look for well-made and well-conceived programs that exhibit little bits of subtlety, humor, and wit - you gotta laugh every time monkeys of two different colors come near each other. There's certainly room for improvement as noted in the review above, but for what it is right now and at its price-point, you can't go wrong.
As a spoof, I thought it would be hilarious if there were a version where the animals could lasso human beings, where different animals had different roping capabilities, speeds, etc. - sort of an antidote to all those buck-and-doe target shooters in the appstore. Of course, this just lays the ground for a whole series of similar themes based on the same line-drawing/grouping idea.
Like the review says, the game may appeal to younger kids superficially, but it's compelling for those of us with OCD. Fun, if you're into clearing stuff, making everything look neat.
Game looks to be a winner. Great reviews - looking forward to playing it.