Invasion is the 14th Expert floor in Monkey Ball, Super Monkey Ball, and Super Monkey Ball Banana Mania, as well as the 23rd Expert stage in Super Monkey Ball Deluxe and the 133rd Ultimate stage with continues (173rd without continues) and the 56th Marathon stage of Super Monkey Ball in Super Monkey Ball Banana Mania.
This stage is considered difficult. It features an overall fairly narrow path with bumpers throughout it. Some of these bumpers move while other bumpers are stationary. There are twelve bumpers altogether. The path at the end has an extremely short, narrow path, which leads to the goal.
To get to the goal, roll through the first three bumpers. Then, roll through the next two bumpers when they are diagonal to each other and with where you can cross without getting hit. Then, roll through the next two bumpers when they are away from each other as much as possible. Then, bypass the next and final three bumpers with the monkey hanging halfway off the floor very carefully. Then, line up with the extremely short, narrow path, and then roll across it at a fast speed and into the goal.