Handcrafted Levels.
Flow has 100 handcrafted levels. Equations get longer, operations become more complex but everyone has a unique way to solve a problem. Because the essence of algorithms lies in their freedom.

Infinite mode.
There is an infinite mode that creates levels procedurally with three different difficulties. So whenever you want to challenge your mind in a relaxing setting, you can open up Flow and play even after you complete all the handcrafted levels.