I am currently working on a tunnel racer space game. One of my favorite parts of flight sims is to try to fly under bridges and between buildings. This was the motivation behind this game. I am building the racing component first. I went with zero gravity airplane physics, which is generally the way most space sims work. The main damage will come from collisions with the tunnel and obstacles. The goal will be speed, where points are awarded for the fastest time.
I am about to implement power-ups, and clean up the UI. Then a free build will be available on the google play store, and soon to follow, the apple store.