So I recently purchased a 2005 iMac G5 iSight (1.9MHz, 1.5GB RAM, 150GB HDD, Airport Card) for $25. It powered up but the LCD was no good so I installed a good used LCD and installed a fresh copy of OS X Leopard. I wanted it for my 9 year old son so he could play his games on it. However, when he plays runescape or minecraft on it, its super laggy. The iMac is connected via wi-fi to my airport extreme with a 15Mbps download speed. The graphics on the game is pretty basic to me but are they still too much for this older iMac to handle? Or is the bottle neck somewhere else like a slow HDD?