Site Navigation Improvement: More Keyboard Friendliness
I have a suggestion that I believe would greatly improve the web interface. I think that throughout the site, we should be able to navigate any lesson-related links that appear on the skill tree, the lesson selection screen after we've selected a skill, and the "Continue?"/"Keep Practicing?" prompt that appears after we finish a lesson, by using the arrow keys and hitting enter. I think this would improve our overall efficiency and speed of navigating the site, and would provide a nice visual touch to the overall feel of the experience, if implemented correctly. What I suggest is to have a light, sparkly color that matches your color scheme, 'glow' around a lesson link when it is hovered over with a mouse, or selected using the arrow keys. Hitting enter would activate the selected button just as when you are practicing a lesson. I've uploaded a mockup of what I think would look nice if implemented. Obviously it doesn't quite matter what the style or color is, as long as it's prominent and obvious. My friend put a lot of effort making it look nice: http://puu.sh/1wCHl.gif Anyways, that's my suggestion and I sincerely hope you consider this functionality. Thanks and have an awesome day.
The lesson blocks already change colour for me. They don't glow like your suggestion, but the difference is noticeable.
I like the idea about more keyboard use. I don't use the mouse during tests. Not sure of the best way to implement it though. The cursor keys are already used to scroll the page.