There are 3'085'851'035'479'212 possible combinations of letters. Of these, though, if they must have a meaning there are way less. Tell me if I'm wrong
Not necessarily; certain forms of encryption have so many possible permutations that they're impossible to solve. A one-time pad, for example, can decrypt into literally any string of text if you don't use the proper key.
That said, this is a computer game, so we have to assume that the programmer designed it with the intent that someone would eventually be able to solve it.