Multitroids is an asteroids clone, with a twist: all of your past lives replay their original actions as you play through the game. This means you can cooperate with past selves in destroying all of the asteroids!
It's written in Python, using (and improving on) the PySFML2-Cython binding. The code is publicly available on GitHub.
Links:
Homepage (Vimeo)
Source (GitHub)
Right now, only a Mac build is available (but the source can be used on any system with Python and PySFML2-Cython installed). If you build it for other systems, let me know - I'd like to distribute versions for Windows and Linux.