Colossal Cave Adventure (ADVENT) was written in Fortran.
Zork (aka Dungeon) was originally written in an obscure Lisp dialect invented at MIT, MDL; but Bob Supnik at DEC ported it into Fortran, and that version became widely distributed.
I used to work for a university, where the software which determined whether students had met all their degree requirements to graduate (such software is sometimes called a "degree audit tool"), was written in Fortran. Why? Well, it was a manual paper-based process, then one of the academics kindly volunteered to automate it for them. And he was one of the mathematics lecturers, and Fortran was his favourite language, so that's what he did it in. Some years later he retired, and without him the software became increasingly difficult to maintain – the university no doubt had some Fortran programmers in the physics/maths/engineering/etc departments, but the central administration's IT didn't. They ended up replacing it with some commercial off-the-shelf solution–no idea what that was written in, but almost certainly not Fortran.