The developers of RWR have responded about IGS on the game's Desura page
hi guys, we already discussed that internally and we came to the conclusion that "pay what you want" offers isn't really what we are looking for, at least not in the beta phase and neither in the couple of months right after the final steam release. It would bring some new players to fill the multiplayer servers, sure but this might be achieved with other solutions which seems more suitable like getting some footage done by bigger youtube personalities where we got some positive feedback but unfortunately nothing happened (yet?).
It looks like we won't be seeing this on here any time soon. Bit of a shame in my opinion, but their attitude seems reasonable.
Sometimes I just sits and thinks, and sometimes I just sits.