I don't know if games can help people face death. But they can definitely help people affirm life. And perhaps that is the best we can do for them.
I'm not one to take the "Tibetan Book of the Dead" approach. Though I admit guided fantasies can be powerful tools for helping people embrace the inevitable. And I'm sure that for some building a shared fantasy about death and the afterlife would be a rich source of very deep fun. Especially if it weren't taken seriously. In fact, how about making it a shared process, you know, each of you take turns adding a sentence.
But actually I'd prefer the life-celebrating silliness of it all. If I wanted to play with fantasy, I'd teach them something like the Frog . If I wanted to get morose, I'd try It Could be Worse, but I'd more likely play something openendedly insignificant, like Plenty Questions, or a good game of Redondo, each of which can lead the living and dying wherever they want to go together.
When I was a college student I worked one summer as a nurse's aide in a horrible poorly staffed, poorly funded nursing home which was formerly called "the county poor house". Although we were poorly staffed and equipped we had a very compassionate and resourceful head nurse. She had a rule that any patient who was dying was not to die alone and no matter how short staffed, one person always sat with the dying patients. I worked there three months and we had 5 deaths. I was 20 years old at the time and had little experience with death to that point.
Anyway....I'll never forget that I had taken my turn sitting with a dying patient, probably for more than an hour. She had begun to have very labored breathing ( the other aides told me this was called "the death rattle"). Another aide came to relieve me....I told the patient I was going, patted her on the hand and said "See ya' later." To my surprise she raised herself on her elbows, taking incredible effort to do this and she croaked out, "....alligator". So of course I said, " afterwhile..." and she replied, "crocodile." She seemed very pleased with herself. I was incredibly amazed that she was willing to spend one of her last ounces of energy in this earthly life engaging me with a joke.