I think they'll sell more copies with a new game though. And a new game allows them to try out new ideas and make that game even more frightening
.
So I'm just hoping for a whole new game that looks a bit like Amnesia. Amnesia is quite similar to Penumbra so I think that's what we'll get! An even better horror game that takes the best stuff from Penumbra and Amnesia and adds some new features.
I don't think Frictional will ever try to make their games casual and appeal to the masses. The masses don't like horror anyway and Amnesia is too scary for them :/.