You did not get in because of your silly accent video.
(As a rule it's a mistake to try to do amusing things in your video. Gags usually make you harder to understand rather than easier, and since we are usually at or past the limit of understanding when reading applications, any loss there is dangerous.)
1. History of shipping stuff
2. Huge ass market
3. Solving a real pain point for indie game devs out there
4. Simple, easily understood, business model
5. Domain experience
Good luck with your business.
EDIT: And it'll be full of more silly things we did that probably didn't matter and that you should also not do.
The developer can strip out all of our assets and republish on any platform without giving us a rev share if they want.
YC tends to select founders who are both talented and confident, so the overwhelming attitude among founders is, "of course I got in," not, "oh wow, I can't believe that happened!"
Of the 80-ish companies in the S12 batch, I can think of 3 with interesting "How I got in to YC" stories, and two of those boil down to, "we had amazing traction." Only Instacart's beer delivery was really a hack, and even that was a demo that their service really worked.
The hack stories are interesting because they're rare. It's important to show off your scrappiness and tenacity, but most founders do that by describing something they've done that produced a worthwhile outcome, not by performing a stunt during the application process.
The only reliable way I can think of to "hack" the YC application process is to apply with a business that you're going to pursue regardless of whether or not YC accepts you. The YC application is full of questions young companies should ask themselves, anyway, and the added confidence can't hurt during interviews.
I feel like the title of this post hints at a similar sentiment.
1. "Give you a heads up on the kinds of things likely to come up for you specifically at interview".
2. "Let you ask us any questions you might have about YC".
It was a 5-10 minutes thing.
What is interesting to us (discovered as we just re-read it), our slight pivot mid YC was to another idea we listed on our application.