Minimum:

OS: Ubuntu 12.04 or newer, other unsupported distros may work
Processor: Intel Core 2 Duo 2.0Ghz or equivalent
Memory: 3 GB RAM
Graphics: Intel Core HD Graphics 3000/4000, NVIDIA 8800 GT, ATI Radeon HD 4850 or better (Open Source Drivers NOT SUPPORTED)
Storage: 3 GB available space
Sound Card: lib32-alsa-plugins or libasound2-plugins:i386 and libasound2-plugins-extra:i386 may be required.
Additional Notes: NOT SUPPORTED: ATI Radeon X1600, Intel GMA950, NVIDIA Geforce 7050

Octodad