As you probably already know an Xbox One demo is planned for the upcoming Forza Horizon 2 and will be released September 16, while the full game will have it's premiere September 30. Now we've also gotten a full list of all the achievements available in the game, and it's a pretty massive list that can be read on this link.
A few examples of what to expect is Rain Master (10 points) which is earned by driving in the rain, Welcome to Saint-Martin (25 points) that's you'll get by driving to Saint-Martin, Worthy of a Sultan (40 points) which is gained by having a whopping 175 cars in the garage and Friends with Benefits (10 points) that really has you ripping your friends and foes off by earning a total of 1,000,000 in-game currency from them.
In the list there are also plenty of achievements that proves Playground Games like their video games, or what do you think of challenges like A Wild Drivatar Appears! and Super Meet Boy?