I have some advice for mys students.
No matter where you publish your final report, send a copy of the report to this list as well.
I don't think that Google can scrutinize the work done by each student. I don't think they can do it. Maybe they will select randomly a few students, or maybe they will use some selection criteria. So, don't think that you are writing the final report for Google.
The mentors don't need your final report either, because we have constantly checked your work and followed your progress. We know who deserves to pass and who does not even without looking at your report.
You are writing this report mainly for your own benefit, so that you can show the work that you have done to a potential future employer. So, please don't write garbage on it but write something understandable, that can present the work that you have done in the best way. Otherwise you just got the money from GSoC but did not get any work experience.
Thanks for your understanding,