Once your developer account is approved on the Vanelton Media Console, publishing new apps and games is fast: you accept the Console's core quality and responsibility rules, and after that you can publish without prior review for each individual submission.
That doesn't mean submissions go unchecked, though. All apps are frequently reviewed post-publication to make sure they still meet Vanelton Media's quality and safety standards described in What are the design and usability requirements for publishing an app?.
If a published app is later found to violate those standards, it can be removed from AppHub, and repeated or serious violations can lead to your developer account being suspended — see My developer account has been suspended. How can I appeal this decision?.