Request #498 From Anna

I read this book around 2011, and it is sort of a sci fi dystopian YA book. I believe it was a series, but is only remember plot points from the first 1-2 books. It revolves around a boy whose sister (possibly his twin) went missing when they were younger and he’s never seen her since. The city they live in separates the have and have nots. The rich life in high rises closer to the sun, and the poorer people live near the ground and eat genetically modified food that has all of their nutrients inside. They do not eat real food unlike the rich people above. The main boy enters a contest at an arcade (I think?) in the poor part of the city and the contest is a flying and shooting game. One person is the pilot and the other is the gunner in a spaceship like device. He teams up with a female character to win the high score (he is the pilot, she is the gunner). They both get sent off to the upper city and he runs into his missing sister there! The children also all have genetic mutations like webbed toes and I remember distinctly one child looks like a Lion. The genetic mutations are how they are so good at the arcade game. I think they find out that they are all being trained to fight in the military and the arcade game was a test to see who would be best for the positions.