@Redeemer: Thank you dude, I didn't know that. Any way as I said before, it isn't standard English character.
@Damocles_: It isn't used only in artworks, Valve use it almost everywhere where Half Life is mentioned. Or do you mean that name which is used on every game box is an artwork? Yeah, you a right that they do not use lambada in spelling (when we read the name), but still, they use it when they write the name, so name includes non standard English letter.