R is one of two unfinished games that MM worked on after Soldat was released and maturing, the other being Crimson Glory. He released it with its source code as a Christmas present to the Soldat/game development community on December 25th, 2006 (Poland time).
A Linux port has been created, though there are a few extra steps needed to have sound work. Part of this stems from the use of MP3+WAV as the formats for the audio in the original release. OGG files have now replaced the WAV+MP3 sounds, as SDL and FMOD both support the use of OGG. Though the files are named .wav in the distribution, they are in fact OGG files.
R is a platform/puzzle/action/adventure game created from Michal Marcinkowski's discussions with Dolny sometime in 2004 and 2005. The game is not finished and never will be. There are whole sections of the game not done, missing graphics, animations, sounds, maps and cutscenes. However the game is complete in its design and is fully playable from beginning to end. So don't worry about the missing maps, it'll just make you finish the game faster and enjoy the magnificent ending. R is released as open source. You may do whatever you wish with it. You can even develop the game and complete it. But just to warn you the source code doesn't really take advantages of c++ language and is a pain in the ass to work with. There is one favor you can do if you have programming skills. Compile the game for linux and other systems. The engine should compile without problems as it is based on SDL and FMod. When you do that please e-mail the executables to: michal.marcinkowski<>gmail.com. If by any chance you would like to continue the project or make a completely new game based on it, there are thousands of ideas waiting that didn't make it into the game. Please contact Dolny if you're interested: maciejgie<>googlemail.com.