Many critcis always blame Linux for the lack of games, although it's not entirely Linux's fault that it has few games. Not all game companies realise the potential of this widely used platform. But some like iD Software do.
About a year ago I was having a problem where after playing any graphics-intensive games for any moderate amount of time (about an hour or so), my computer would completely shut off with no warning. I figured it was the fan or the thermal paste going bad, so I ordered some Artic Silver 5, cleaned out the fans and applied it to the GPU. I didn't have any more issues for probably over a year.