This is a 2D game engine and shmup iPhone video game I developed. The game engine uses a fixed physics time step with linear interpolation. The full version has 30 levels and the lite version has 12 levels.
I read these game programming books during the project:
It's built with C, C++, Objective-C, Python and OpenGL ES 1.1. The project date is 2009 to 2012. This game is no longer available in the app store.
Here are some screenshots:
And here is a video: