When chatting with Denis Shergin, Unigine Corp's CEO, on Friday, it appears there will be a minor delay in their planned summer release. "It seems that in order to deliver a good game we need more time." Additionally, Unigine Corp is still held up by Valve (for Steam) and other publishers.
Of course, if you pre-order the OilRush game there's early/beta access. These public development builds are frequently updated and just on Friday morning they released OilRush v0.70, which provides various fixes and minor updates. It's not that the Unigine Engine isn't ready to shine with this game, but where the developers are still busy is on the single-player campaign storyline and ensuring it makes sense and is a fun experience. The price of the game with pre-release builds isn't expensive at all either, at a price of just $19.95 USD.
For those unfamiliar with this Windows / Linux / Mac OS X game, below is the original trailer for OilRush.
There's also their newest trailer embedded below.
We like Unigine a lot since the studio is especially friendly towards Linux and their engine is the most demanding OpenGL engine that's natively available for Linux.