Thanks for the info.
Why is it getting removed?
I don't know for sure in this case, but it's often that some license was time-limited. You might license the music for x-years, or get a license to distribute some third-party software library with your game. With the license time-period runs out the publisher either has to pay to renew the license or stop selling the game. In either case, people who bought get to keep what they have.
Very likely a license problem, with the Games Workshop not renewing the W40K license for HeroCraft (the game developers). I hope not too many recent games actually get unlisted from Steam because of music licensing issues, when a simple solution would be to remove said music in a patch.
Hmm, I was like "Sure, it's $4, why not?" But I can't actually buy it. Steam says "There seems to have been an error initializing or updating your transaction. Please wait a minute and try again or contact support for assistance."
Steam is a video game digital distribution service by Valve.
Steam News | Steam Beta Client news
Useful tools:
SteamDB
SteamCharts
Issue tracker for Linux version of Steam