To activate the cheat mode in X-Com: Apocalypse Tactical, hold down Alt while typing TAC CHEAT. The message bar will tell you if it worked. If not, press Alt and any key other than T. Then try again. To enter one of the following cheat codes, hold down the Alt key while pressing any of the following letters:

To exit Cheat mode, hit Alt-Esc.

F -increases musical intensity

G -decreases musical intensity

H -toggles hidden terrain

I -toggles god mode

K -kills all hostile units

R -shows frame counter

T -toggles training mode

V -toggles hidden units

W -toggles weightlessness