Strategy
Many players find the game becomes quite difficult by only the third or fourth level, given the number of balls on the field at once.
The trick to playing successfully is to build corridors. To build a corridor, start a pair of walls growing close to another wall, and time it such that one of the walls will be hit by a ball and one of the walls will not, and thus become permanent.
Building a corridor
Building a corridor
This will leave a narrow corridor only a few squares high on the field, surrounded on three sides by walls. Wait for the balls to bounce into the open end of the corridor, and close the corridor behind the ball with a new wall. Although you will most likely lose a life for each corridor created, you can trap several balls in a single corridor.
Capturing balls in a corridor
Capturing balls in a corridor
A final tip — take your time! There is plenty of time, as shown in the Time display on the right hand side of the screen. Rushing will just get you in trouble!