When an otherwise excellent game has bugs, it sucks. Plain and simple. Glitches that remove important characters or prevent events from triggering can ruin an entire experience or force a complete restart just to get around the issue.
The only thing worse is when the patch to fix these problems actually messes up the game further, which is the case with Polytron's mind-bending platformer Fez and its patch that went live this morning. The game update has reportedly been corrupting save files. Joy.
Fortunately, the fine gentlemen and ladies at Polytron have immediately recognized the issue and offered what help they can. If you've suffered data corruption, they recommend deleting the save cache for the game to resolve the issue. And of course, avoid downloading the update if you haven't already.
You can find the complete details for what the patch fixes and stay up-to-date as to when the patch issue has been resolved on their blog.