I was given a small project to complete over the weekend for an interview. Not a very difficult project at all. Fortunately, I was able to spend all my time designing, developing, and testing the application rather than having to research something I wasn't familiar with. 

After working out a couple of critical bugs, I am left wondering if I should add anything more to the assignment. Assume, at this point: 

 - everything is commented
 - no bugs found
 - any known exceptions are handled
 - 8 hours remain in allotted time

**So, is it better to go ahead and submit a bug-free, working assignment earlier than the deadline?** 

...or ...**Take the fully allotted time to add a feature (obviously something simple like logging)?** 

...or ...**Provide a list of TODOs that could improve flexibility, scalability, or general usability?** These would be improvements that simply could not be done within a day or could introduce too many issues to resolve in the time allotted.

FWIW: the project consisted of creating a multi-threaded sort controller implementing 3 different sorting algorithms; results to be displayed on WinForms UI.