A couple of minor criticisms (as an intermediate Vim user): - I felt like it was too easy to just stare at the key instruction on the top left and just ignore how you're navigating the block of text itself. As you are letting people know what commands are being introduced in the next lesson, maybe they should only be shown if the student wants a hint? - It seems like the only way to go to the next lesson on completion (without using the mouse) is to tab once then hit enter. Maybe that could be a keyboard command as well? `n` maybe?
I defaulted to showing them so that completely new Vim users don't get stuck or lost during the lessons, but maybe you're right and I should default them to off after the first couple of intro lessons.
To put it another way, the user is a reader and hunting useful information requires parsing through the text. The more there is that isn't useful the more work the reader has to do and the more likely misunderstandings are.
It might also be useful to have the key bindings available as an interactive element in the interface. Even considering how that would effect the bread and butter page might be a useful exercise regarding how information might be organized.
Good luck.
