Microsoft has given the Xbox Live Achievements Section a makeover, by adding a sub-section dedicated to non-gamerscore challenges.
The motive behind implementing these changes is to make the creators can “deliver more interesting, complex, and fulfilling goals and rewards to you”, as mentioned by Cierra McDonald, Program Manager, Xbox Live Achievements.
One of the major changes is that music and video apps have achievements. But they won’t influence your gamerscore in any way. The apps will have many bonuses and rewards. The rewards could be new maps, new characters, (digital) artwork, stat boosts, subscription extensions, early access and sneak peeks. The tricky part is that Achievements can be displayed in two ways: Achievements and achievements.
A game’s Achievements will be available as soon as it’s launched. You can complete the Achievements whenever you want to, except when you’re playing in multi-player mode, and the games’ servers are down.
On the other hand, a Challenge has been described as an opportunity. Complete the Challenge, get the reward. But there’s a time limit. Thankfully (or not) it won’t affect your gamerscore. Usually, Challenges will be set for a whole group or community.
The Achievements are tied with the cloud services, and that means the creators may even increase them over time, giving you more chances to increase your gamerscore.