The term is not limited to neurology. The first part in hearing the term in lecture was that its reference was far more specific than the term's general (albeit rare) usage. Any time in which things have a different obvious faculty of perception, memory, reflection, etc, and yet blend across each other by some abnormal or linking circumstance is considered synesthetic, and the phenomenon as synesthesia. Though saying that it is used in designing a video game might be too strong a word, the term itself is not necessarily incorrect.
I'm sorry for nit-picking in reverse, but I don't see why something with a clear, even if abnormally written, intended meaning should be chocked up to error.
