Control your spacecraft with the power of the sun. Try not to drift into interstellar space or to fall into the sun. Collect the comets.
Press H in-game for some help. Arrow keys are used to tilt the sails. The main goal is to collect the comets.
Note that this blend will only tun on Linux and on 64 bit Windows (as it uses some compiled C code to accelerate computation. I do not have access to a mac to compile/test. With some luck, you may be able to use the makefile in Data/Scripts/Makefile to build it for mac.