There is now a level based game mode called the challenge mode that has been added since the most recent update to the game. This mode is actually quite similar to the endless mode, but there are one or two designated types of obstacles that you have to bounce the ball through. They will be the same every time you play that specific level.
Also, for the challenge mode, unlike the endless mode, you will only have to go through a specific number of circles before crossing the finish line and beating the level. Generally it will be between three and five circles depending on the level; however, for easier levels it can be less and for harder levels it can be more. Currently there are just over 100 challenge levels. Expect more of them to be added to the game with each successive update.
You have an easy set of levels, a medium set of levels, and a heart set of levels. Go to this mode anytime you want to in order to practice specific obstacles, especially the hard ones as they will give you really fast reflexes. All of these new obstacles can now show up in the endless mode as well, so you will have to be ready for them.
In addition to this new game mode, there is now a type of currency in the game as well as something that you can purchase with it. Stars are the new form of currency that have been added to Color Switch, and the higher the score that you earn, the more diamonds that you will get in the level. It is generally much easier to get a lot of stars on the endless levels as opposed to the challenge stages.
When you earn enough stars, you will be able to purchase a new shape for your ball. All that the purchase really does is to change the appearance of the ball; the levels all continue to look the same, and continue to play the same. Some balls are cheap, costing as little as 20 stars; other levels cost a whole lot more. One specific ball costs 999 stars to purchase.
If you go to the bottom of the new circles store, you will find a set of them that cannot be unlocked by paying with them with stars. The only way to unlock these circles is to complete a specific number of challenges. One particular circle can be unlocked by completing 10 challenges; there are a number more of them, including the toughest circle to earn, which is unlocked by beating every single challenge mode level in the game.