By shooting walls at the end of hallways, you can sometimes open up
secret passages or find hidden power-up's. You may have to lay down for
this to work. You can determine the correct position (i.e., standing or
laying down) by observing in which one your laser beam is more quickly
absorbed into the wall. The position in which your laser is quickly
absorbed is the correct position. Once this is determined, fire into
the wall until it opens or until the power-up appears. Some require
more shots than others, so be patient. Note that you cannot actually
get the power-up's; they increase your power when they appear. Below is
a list of rooms with secret passages or power-up's. Secret Passages are
colored purple on the map below.
(A,1) power-up
(B,2) passage
(F,1) power-up
(F,3) passage
(H,3) passage
(N,1) passage
(P,2) passage