When the first Portal game came out, I wanted to play it but it was on The Orange Box which was rated M. (I think) I remember that I didn't want to play it for that reason. (I forgot to mention that I was way more young.) :D
I've played Portal 2 and I love it! I want to play the first one. Note that the first Portal game was rated T. I found that out about a year later so I asked my Dad if I could play it. He threw it out. :(