Homeworld 2 game not working on my mac?

I just got the Homeworld 2 game for my macbook, and installed it without issue. However, when I tried to run it I got an "unexpected error". I then tried to restart my computer, but now it will not turn on fully (I get a grey screen).

I checked the system requirements on the box and found that my macbook surpassed each one greatly. How do I 1. get my mac to actually turn on fully now (yes, I tried turning it on in safe mode by holding the power button), and 2. get Homeworld 2 to run on mac.

Thanks.

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Update: Finally got my computer back on, and as it turns out its a video card problem. Is it possible to upgrade a macbook's video card by sending it in somewhere or doing it yourself?

Thanks again