It's the game that made me stop using cheats. I was young and discovered cheat codes and used them in every game that made them available.
I remember completing Deus Ex and finding it "just ok", but then I read how people talked about it, and realized that taking away the challenge from games was making them worse!
Never used one again, aside from when I discovered Cheat Engine, which was amazing for somebody who was starting to get interested in programming.