The further you progress in Challenge mode, the more tricks you will learn.
Gems
Gems are the game's premium currency and are awarded along with coins for completing the achievements.
Knee juggles
The knee juggle is the second trick that can be learned. The ball will be landing towards your feet, and your character will not lift up their knee until it is almost at the contact point, leaving you little time to decide if it is a knee juggle or only a regular foot juggle. If you see a ball coming down towards your feet, be prepared for either.
Team leagues
At level three you will be able to play League mode. This is an endless mode where your goal is to see how far you can get. You can also join a Team League. Whenever you play League mode while on a team, your scores can be compared to your teammates. You will also earn bonuses for you and your team. There are also some achievements that require you to be on a team.
Tricks
Complete all of the tricks in a level perfectly to double the end of level experience reward. Purple sparkles will appear from the ball if you tap perfectly. If you make a mistake and miss a perfect hit, intentionally allow the ball to hit the ground to reset the level faster than returning to the menu.