Regarding your feedback...yeah, I've gotten that feedback a lot. Thats part of the reason why I built the practice mode. Did you get a chance to try it? It doesnt have the timer and you can take your time counting notes to get better. And my favorite part: You can pick and choose what frets and strings you want to focus on.
But your point still stands: There is a need for a gentler introduction and I do have that in mind: A Duolingo style Spaced repetition approach that starts off with 5-7 notes a day and builds up from there. Once you're done with the course, you can play the game to reinforce and test the concepts. What do you think?