I'm already deep into development of the game, but it's still early.
I opened up an IndieDB page, it has some screen shots. In short, Shmup God is the best shmup ever made, all the fans of classic shmups will worship the game.
The game is a true 3d game with realistic graphics, a bit demanding on the video card / CPU side. Once I finish all the features the minimum system requirements will be established, but in my experience, since the models will be complex, the models and graphics on the screenshots are not finished, and there will be thousands of objects on screen simultaneously, 2.2 Ghz and a decent Shader 2.0 video card would be necessary to play the game, without FSAA (Full Scene Anti Aliasing) turned on, at maximum FPS.
http://www.indiedb.com/games/shmup-god