Trying to play CS:GO on a Mac

[Eureka]

So, I've been trying to get CS:GO to run on this macbook pro. It's actually not mine but I use it on the weekends and so I want to get it running. Here are the specs:

Model Name: MacBook
Model Identifier: MacBook5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 2 GB

OSX 10.5.8

However, when I try to run CS:GO from steam, it gives me an error:

Failed to start game (unknown error)

I am opted in to Steam Beta update, and CS:S runs without an issue. Any help? I rarely use macs so I have no idea where to start...

 

[crab0]

You need 10.6.6 minimum according to Steam to play CS:GO, CS:S minimum is 10.5.8.