In the mission, when they throw off from the helicopter (together with the machine and 10 cartridges), it is not necessary to kill the first monster and spend the precious 10 cartridge. T.to. Mutants are not distinguished by a special mind, you can just get around. When you threw off, quickly take the machine and run up to the stone on the right side. Monster will run to you, and you will go around the right side at this time and run to the cliff. The mutant will go around the stone for a long time and will only see you when you jump off (this way I never let me down).