To the Left, To the Left

To the Left, To the Left is a special mission in which you must defeat forty waves of bloons while you can only put towers on the left side of the screen. Every 10 rounds, your towers will be shifted even farther to the left (if they run into the path, they will be pushed over it). When you complete this mission, you get $200 Monkey Money. However, upon completing this mission, you will get the option to do the mission To the Right, To the Right. If you choose to do that mission immediately after completing this mission, and complete it as well, you will get a bonus of $100 Monkey Money, on top of the normal amount of Monkey Money you would get.