You didn't have trouble reading it, because the author deliberately kept the first and last letters the same, and referred to Typoglycemia, https://en.wikipedia.org/wiki/Typoglycemia, which has shown that you can (often, not always) mix up the internal letters and the works are still very legible.

In doing this, I think the creator was specifically trying to make a Typoglycemia simulator, not a dyslexia simulator, since the original quote said nothing about the first and last letters remaining the same.