I did the first challenge or exercise, but I was honestly a little surprised that Vim motions aren't able to be used to choose the next exercise(s) in the sidebar that becomes visible. That could potentially be something that the player unlocks later on as well.
Agreed, it would be nicer if the whole cell were clickable. I’ll work on this. I also recommend to use hjkl to navigate and Space to select. I think that’s more fun :).
One note: It might be useful to keep the "undo" prompt when the user messes up after the first two prompted lessons for a clear recovery path.
Thank you for making this!