minimal:
reqprocessor: 1.8GHz Intel dual-core and above
reqgraphics: Intel HD5000 and later. Minimum 512MB VRAM. Pixel Shader 3.0 support. Deferred lighting support (most 2005 and later cards support deferred lighting)
reqmemory: 2 GB RAM
reqdiskspace: 2 GB available space
reqsystem: OSX 10.8 Mountain Lion

recommended:
reqgraphics: NVIDIA GTX600 or ATI HD7000 series with 2GB VRAM
reqmemory: 4 GB RAM
reqdiskspace: 2 GB available space
reqsystem: OSX 10.9 Mavericks