Developer Polytron announced in their blog that the Fez update that was supported to be released earlier in June was rejected by Microsoft on the 25th May "because of two critical issues."
According to the blog, "One of them was resolved quickly, the other one (a random crash when upgrading the game from trial to full game) was impossible to reproduce or test on my side. We tried with MS to get the issue ignored because I had no tools to resolve it, but after weeks nothing moved.
On June 8th, I finally got access to a testing method that allowed me to reproduce the issue, and it got fixed completely today.
So it’s going back to Microsoft right now, and should enter certification again soon. Expect a ~2 week delay, but it’s coming! Finally!!"
Fez was released on the 13th April, earning rave reviews including a 9.5/10 score in Strategy Informer's review.