Evidence that you can actually do the work is what is essential, those are only examples. Generally, the broader and more interesting the work at the job you're applying for, the broader the examples of your work, and other evidence, like working an example problem(s) in the interview, will be required.

The important thing for the company is that you provide more value than you cost, so they try to weed out people that either can't do enough work quickly enough or will require too much hand-holding to be practical in their work environment.