At any time during gameplay, a cheat code can be activated as many times as needed to receive one free medicine bottle, allowing players to stock up on as many health items as they need to get through the game. This was most likely not meant to be seen by players and was possibly intended for debug purposes during development. The code involves standing still, pressing Up/Down/Left/Right and repeating this combination 16 more times in a row.

At any time during gameplay, if you press Down 100 times in a row, Rambo's combat knife will automatically gain 15 EXP points. This cheat does not have a limited use and can be activated as many times as needed, suggesting this was meant to be a code used for debug purposes during development and not to be used by players.

There are two hidden methods to obtain permanent unlimited ammo. In order for both of these methods to work, Rambo's combat knife needs to be at Level 1 (20 EXP points), which is difficult due to Level 2 being only 320 EXP points away, making the chances of the player collecting the necessary ammo before Rambo levels up slim. As such, these methods were likely only intended for debug purposes and not meant to be discovered by players. If you manage to collect exactly 2 throwing knives, 3 arrows, 4 exploding arrows, 5 machine gun rounds and 6 hand grenades, all ammo and health items will be permanently refilled. The other method to get permanent refills is to have an ammo count of exactly 77 throwing knives, 77 arrows, 77 exploding arrows, and 77 machine gun rounds.

It's possible to avoid the cutscene where Co dies. If you do this, she will still be alive at the end of the game.