Press 'P' to pause the game and type "ASTRA GTE". Now press '1' for extra lives or press '2' for 999 units of ammunition.
Other sources give this as the cheat.
Pause the game and type "SMURF". Now press '1' for extra lives or press '2' for 999 units of ammunition.
To unpause press 'P'. Pressing 'F1' and 'F2' will now reimburse both player's lives.
Supplies of ammunition come in two forms : 20 shots either for cannon or machine gun so don't go out of your way to collect extra bullets unless ammo levels are low.
Transportation tiles make machine gun soldiers appear frequently.
'Hug' the walls as often as possible.
Also do not move off the end of a wall while someboby is firing at you, or you will be shot.
Electric doors are operated from a distance, watch for men on the other side.
On later levels (8+), men will appear from nowhere (teleportation devices possibly) - be on your guard!
Cannon is more affective than gun as it passes through men, dead useful for racking up the bonuses caused by multiple guards standing behind each other when a cannon fires.
Use diagonal movement to move that bit faster towards cars, barriers, buildings (or anything else that provides cover from enemy fire).
Level 1 (3 bombs to plant)
Nice and easy level to start with. Just watch for the men standing
guard. Go along the top to avoid the lower generators where the
enemy tends to hang out.
Level 2 (3 bombs to plant)
Again very simple look out for men appearing from inside cars as
there are quite a few along the top. Try to stay along the bottom.
Smart bomb the group of men by the exit for convenience and to save
lives (yours!).
Level 3 (3 bombs to plant)
Watch the acid! And also the machine gun guards near the exit. Take
a wide berth past the flame throwing guard, his long range fire
isn't nice- hug the bottom if you can and then sneak up the side to
the last bomb area and exit.
Level 4 (4 bombs to plant)
Here are some electric doors to play with; just watch for men on the
other side! Also plenty of men appear using the tiles near the exit.
Run diagonally straight up to the exit and pray (judicious use of
smartbombs is recommended.)
Level 5 (5 bombs to plant)
Five bombs to place so waste no time. Like level 2, watch for the
men in cars. To get over the moving floor simply walk along the wall
as the floor starts to close. You can get past the wrecking balls
without too much problem providing that the nearby guards have been
eliminated.
Level 6 (5 bombs to plant)
Plenty of guards to blast you now in long corridoors (useful to have
a cannon ready for this level). Hug the wall edges when sneaking up
on guards and use the boxes for cover. Watch for chasms and machine
gun guards covering crosses on the far side. Also groups of guards
just over the bridges.
Level 7 (4 bombs to plant)
There are a lot of touch sensitive cracks in this level's floor. You
can see where the ground is cracked so best avoid altogether: Taking
the lower route is generally best as there are less holes to avoid.
On this level Kung-Fu men appear to attack, they just need a touch
to kill you! Shoot the controls to open the bridge.
Level 8 (6 bombs to plant)
More electric doors to contend with. Rather simple stuff really but
the level is quite long winded, and can prove a long haul if you
don't use the map to remember the correct route through. Time is
tight so don't stop to admire the view and from this level, men
start appearing from nowhere so be on your guard!
Level 9 (4 bombs to plant)
Time for the conveyor belts. Just move the joystick the other way to
stop movement, try to cross the belts at the edge of the area where
the belt emerges from the wall. There are 5 men guarding the third
cross, so be careful. Also there are men on the exits so a
smart-bomb or two comes in handy.
Level 10 (5 bombs to plant)
A very dangerous level, as men appear frequently and you can easily
be caught in crossfires. Stay alert and keep on the move, hugging
the walls when cornered. Once again there are guards on the exit so
bomb them.
Level 11 (5 bombs to plant)
This is easy compared to the previous one! Using the radar watch
where guards are on the other side of the groups of conveyor belts.
Stick to the sides when crossing the last set of 4 conveyor belts.
Also, there is an ambush over the bridge so either arm up with
cannon or smar-bombs.
Level 12 (4 bombs to plant)
Men stationed practically everywhere so keep that trigger finger
pumping! To use the moving platforms over the acid, just push right
(or left) and hold it there to walk over. The last area is a simple
maze, but the fencing is deadly to the touch close up. Take your
time, better to arrive at the exit late than never at all!
Level 13 (5 bombs to plant)
The cannons fire randomly when you're in range so quickly sneak
round the corners and move down out of the line of fire to nip past
the cannons, when possible.
Level 14 (10 bombs to plant)
Things get tough with ten bombs to plant in the men-makin machine
level, so there is no time to stop! The bubbles are harmless, the
men aren't.
Level 15 (5 bombs to plant)
The middle is a long maze, with men appearing all over the shop so
hug those walls! For the lasers the sequence of blasts is: 1 down, 2
down, 3 down, 4 down, 8 up, 7 up, 6 up, and then 5 up before
repeating. Time it well or else!
Level 16 (0 bombs to plant)
The final level and you'll be pleased to hear that there are no
bombs to plant! Trouble is you've got to time it well to get through
the mesh doors. Go in the middle and run through just as they start
opening (without stopping). You should make it. For the conveyor
belts stay in the middle watching for guards as you move across.
Then it is plain sailing to the end!