Unlimited energy:

Load or reset the game, then execute the following BASIC command before running or restarting the program. 

POKE 42386,189 

Unlimited ammunition:

Load or reset the game, then execute the following BASIC command before running or restarting the program. 
 
POKE 42043,189


                              ALIEN
     Written by Darryl Reynolds (Softgold Talkie Adventure)
          Walk Through by Dorothy Millard (C64 Version)
                                
                                
Notes:
1.   It is recommended that you save the game at the garage
  window, as a certain number of moves must be made before it is
  safe to enter the window without getting caught.  If the owner is
  there restore your position and wander around for a while before
  trying again.
2.   When at the entering the dark office window there is a
  chance that you will be caught, so save before entering, then if
  caught simply restore and try again.
3.   In the maintenance room a patrol will come along regularly.
  When the message “Here comes a patrol” comes up you have two
  moves to get to safety.  Safe places are the large building
  surrounded by boxes or in the vent once it has been opened.

Walk Through
(Start in a car on a desert road), LOOK DASHBOARD (see glovebox),
OPEN GLOVEBOX, LOOK GLOVEBOX, GET CAMERA, LOOK GLOVEBOX (again),
GET PENKNIFE, S, S, W, W, S, E, E (back of garage), OPEN WINDOW
(using penknife), SAVE (see note 1), GO WINDOW (garage workshop),
LOOK BENCH, GET BOLTCUTTERS, GET SAW, N, W, W (by wire fence),
CUT SAGEBUSH, GET BRUSH, N (secluded track where your car is),
COVER CAR (using the brush to hide it), S, CUT FENCE (using
boltcutters), DROP BOLTCUTTERS, GO FENCE, S, E (by tall cactus),
LOOK CACTUS (see a grill), LOOK GRILL (has a big lock), CUT LOCK
(using boltcutters – this is an important exit for later), W.

E (outside dark office), OPEN WINDOW, SAVE (see note 2), GO
WINDOW (inside office), LOOK TABLE (see drawer), OPEN DRAWER,
LOOK DRAWER, GET DISK, LOOK MAP (a plan of the complex), LOOK MAP
(again – note number 825), LOOK DISK (looks like a credit card),
W (behind crates in a compound), OPEN CRATES (using penknife), GO
CRATES (just in time here come the men... you are moving... the
crate is dropped), S (large building surrounded by boxes), W, N
(maintenance room), OPEN TOOLBOX, S, E, W, N, LOOK TOOLBOX, S, E,
W, N, GET SCREWDRIVER, S, E, W, N, REMOVE VENT (using
screwdriver), GO VENT (dim air duct), DROP SCREWDRIVER, N
(maintenance room), GET OVERALLS, GO VENT, E, S (room with small
beds), DROP PENKNIFE, DROP SAW, GET SILVER (suit), GET BOOTS (do
not wear yet), N, DROP BOOTS, N (large hangar), WEAR OVERALLS, W
(laboratory), LOOK BOTTLES (find a film), GET FILM, INSERT FILM
(in camera).

E, TAKE PHOTO (of the UFO), LOOK UFO (see control – here come a
patrol), S (into duct to hide), GET BOOTS, N, LOOK CONTROL (see a
slot and numbers), INSERT DISK (in slot – here comes another
patrol), S, N, PRESS NUMBERS (which numbers?), 825 (a door opens
in the UFO), N (inside UFO), E, GET HELMET, W, S (the aliens
discover the theft so don’t hang around), S (duct), WEAR BOOTS,
CLIMB HOLE (must be wearing boots – to top of duct), DROP BOOTS,
S, W, N, N, N (secluded track where your car is), E, E, N, N, N.

                              Phew!
                      You have eluded them.
          Now back to Sir Lodericks with the evidence.