To me, saying Half Life is meant to be spelled with a lambda is like saying the movie A.I. is meant to be spelled with the silhouette of a little boy.

All they're doing is incorporating a logo into the title. The distinction between this and actually using names spelled with a non standard English letter is obvious -- one is purely stylistic and those searching for it will unanimously use the standard English letter it's meant to represent; the other is actually a spelling issue, and will divide related material between those that use the non standard English letter and those that replace it with something from the English alphabet.

Jibb