You must cost 19.99 usd to buy this game but it is free now for only 48 hours.
First, you go to store humblebundle
Second, you log in (or register), click get it free and check out
Third, you will reiceive a key. Open steam software and type it. Enjoy!!
SYSTEM REQUIREMENTS
Minimum:Windows</
OS: Windows XP, Windows Vista or Windows
Processor: Intel Pentium Core 2 Duo 2.4 GHz or AMD Athlon X2 2.8GHz
Memory: 2gb RAM
Graphics: Shader Model 3.0 Graphis Card w/ 256mb of memory, NVIDIA GeForce 7900GS or ATI Radeon 1900XT
DirectX:Hard Drive: 10GB of free hard drive space
Reccomended:
Windows<
OS: Windows Vista or Windows 7
Processor: Intel or AMD Quad Core 2 GHz+ CPU
Memory: 2 GB RAM
Graphics: NVIDIA GeForce 260 or ATI Radeon 4850
Hard Drive: 10GB of free hard drive space
Supported Languages: English, French, German, Italian, Spanish, Dutch
Won't forget to upvote and follow me @huymole if you find its benefits