hah, since you actually got a game running i think you're fine. the cpu usually starts throttling before any damage is done, so the thing you'll notice if something is wrong is that performance decreases after some play time.

the main thing to look for is if you get a massive spike in temp the instant you put the cpu under load. if you see temps climb over a few seconds that means the thermal mass of the cooler is wicking the heat away properly. another thing to check is whether changing the cpu fan speed changes how fast the cpu cools down.

if your temp doesn't level out under load, or increases during idle, then your cooler is too small.

if you're nervous anyway (as i was), thermal pads have gotten really good.