I just submitted my application about six hours ago, and decided to login to their website to just become familiar with the layout. The current status of my application is marked, "Application Unsuccessful." Has anyone experienced something similar? I just don't know why or how it would have that status after six hours. I haven't received an email or anything.

Sorry about the unsuccessful status, this exact thing happened to someone i know. My friend submitted her application then she checked her status after approx 7-8hours and the status had changed to unsuccessful. She got the email 3 days after. We came to the conclusion that it was the ATS that did this and not any human recruiter. Google ATS (applicant tracking system). There are certain keywords or skills or quota the recruiters put in the system for it to first filter people out.The candidates that get rejected quickly has probably been hit by the ATS.
Example they might want to hire people from a certain country, speaks a certain language, are in a certain age group, have certain skills etc etc. The list is long. That is what they put in the ATS for it to filter people. Also I have heard the ATS do spot people that had not waited 6 months before re-applying. Or created multiple accounts etc. There is a bunch of reasons for this.
This is what we think anyway