I honestly think that dyslexia is a range of undiagnosed conditions. It's nothing like the simulation for me, but it's not the first time I've heard of letters jumping around.

Dyslexia simply means having trouble learning to read. Being diagnosed with dyslexia does not give any indication as to the cause of the dyslexia. The formal definition in the DSM-5 is:

"a pattern of learning difficulties characterized by problems with accurate or fluent word recognition, poor decoding, and poor spelling abilities."