I played the game once and almost got all the achievements in the game. But I used the cheating codes to get the three challenges-related achievements. Now I want to replay the game and get those three achievements on my own. Can someone teach me how to reset the achievements? I don't mind if I have to reset the whole game....

this game is so sigma ohio fanum tax kai cenat rizz ishowspeed gyat grimace shake hear the roar.

yes or no

portal

Portal Ambition (demo) : Highly Recommended. The game is honestly not bad. It got me interested, and now I'm dying to see the whole game. Gamma Energy : Recommended. The game is pretty tough, but i got through the tests :) The boss fight is a pain in the ass though, and now I'm stuck :( Blue Portals : Highly Recommended. Probably the first Portal mod ta...