This is definitely a geeky achievement, and then some. After all, the Google Nexus S was launched more than 4 years ago, and that would be April 2011 to be exact. As for the last update which was released for the handset, it would be Android 4.1.2 Jelly Bean as it hit the device in October 2012, and that was also when Google decided to officially stop all support for the device.
Grinberg claims that this particular Android 6.0 Marshmallow port for the Nexus S was to show how it is possible for older devices to run on the latest Android platform, and this particular build is deemed to be stable as it will support the cellular radios, sensors, NFC, Wi-Fi and Bluetooth connectivity, a working camera, and an accurate GPS, now how about that?