Uhh, I think the OP was thinking about the game causing too much over-heating on his MBP. That's what immediately got my attention the moment he mentions playing a game on a laptop. I think that was the gist of what the OP was concerned about. The OP should elaborate a bit more.
Anyways, I can't answer him directly, since I no longer own Mac laptops (I stick to iMacs for my desktop these days). Nor do I know if CSGo is considered a "graphics-intensive" shooter game by the standards of a 2012-12014 Mac hardware, as I don't play that particular game.