On the title screen, type "HAMBURGER". Each time you type one of the letters correctly you will hear a gun sound effect and once the entire word is typed in you will see "CHEAT!!!" appear below the scrolling credits. Press your joystick button to start and then during play you can press any of the following keys:
'F1'__________Moves you to the level 1 starting point 'F2'__________Moves you to the location of explosives 'F3'______Moves you to the bridge you need to blow up 'F4'_________Moves you to the village (hidden tunnel) 'F5'_______________________________Invulnerability on 'F6'______________________________Invulnerability off
If you also type "-HILL" (where the hyphen is the minus on the numeric keypad) after you have typed "HAMBURGER" it will activate a second cheat. When the credit screen re-appears the words "MEGA CHEAT" will appear at the bottom.
NOTE: Don't use the shield when going through the trapdoor!
The jungle map is always the same so you can memorize the route.
If you are in the jungle and hear a shot, jump fast. You are being shot at from off screen. You can kill the underground snipers by using grenades, or better yet, just jump over them. Another idea is to shoot three or four shots when changing screens, just in case.
When you have placed the explosives on the bridge, wait beside the second bridge and shoot any enemy that pops up. A package will be deposited and if you get it, a hit point will be removed from you and your morale will go up.
Ignore the first three huts. Go into the fourth hut and kill the soldier hiding there. Search to the right side of the sack of rice and you will find a map. Ignore the 5th hut and enter the leftmost hut (the 6th one). You will find a torch in the large bowl. Now go back to the 5th hut and down the tunnel. If you are using the cheat mode you will be asked whether to proceed but this is covered up by the cheat text. Press 'Y' to confirm and you will enter the tunnel.
Keep an eye on the map and use it! The top left room contains the Captain. As soon as you enter the room, kill him and search the drawers for the flairs. There is a compass near the top in the middle of the map. The second set of flairs is near the bottom of the map in the middle. Exit at the lower right side of the map. Keep shooting but in short bursts. Ammo is very hard to find here. Keep moving!
Throw a flare and start shooting the enemy. Use the flares as much as possible, and watch your bullets very carefully as it is very easy to run out!
Shoot, shoot, shoot. Time is short, the easiest route out is go left and right alternately.
The easiest way to kill the seargeant is to stay out to the left or right edge of the screen as he shoots, and then move into the center of the screen and throw a grenade. You do not have unlimited grenades so line him up before you waste a shot! After several hits he will die and you can move to the top of the screen to complete the game.