Gold Plasma
If you need more Gold Plasma to upgrade your ghost in the ghoul room, go onto the high score board. Keep playing the same missions repeatedly until you have enough Gold Plasm to upgrade your ghost to its full potential.
Helpful Hint/Glitch
When on a level with a jail cell (i.e. The Unusual Suspects), don't place a ghost in the cell to scare them, unless you let the prisoners out (by having the lock, the machine on the side with the red buttons, short out, etc.). If you don't the people will disappear (some sort of glitch), and you will not be able to finish the level (it will say that they are still there, but there aren't).
More Gold Plasm
If you need more Gold Plasm to upgrade your ghost in the ghoul room, go onto the high score board. Keep playing the same missions repeatedly until you have enough Gold Plasm to upgrade your ghost to its full potential.
Freeing wavemaster...