I think anik is just curious how LFS would perform on that particular computer, as he already has another gaming rig which he plays regularly on.
I agree with both responses, Celeron is very weak, in fact the entire system is weak, so 30 fps would be normal for such a system.
On another note, I notice you said it's a plasma tv. I think it might not be a good idea to have a computer hooked up to a plasma tv, it could cause burn-in for parts of the screen which are always visible (such as the taskbar in Windows). If things remain on the screen for too long, they will be burned into the screen and if you start watching a movie or something you might see a ghost of your taskbar. It's a big disadvantage that plasma tvs have, that's one reason why they're not as popular as they once were.