How do you get to level 22 on orb 2?

There is no level 22 on Orb2 or Orb2 TNL.

There are Bonus Levels including belts and endless levels.

There is no level 22. There is not actually a level 21 -- it is the end screen.

There are 20 playable levels and 5 bonus challenge levels on the main menu.

(to access, enter the level 21 code, which is 51210)