How do you win motherload

just keep digging downward (its smart to dig in a straight line) when your deepness tracker starts playing up your getting closer when it looks like you've got to a cave go to the right drop down and Mr Natas (Satan backwards) will come out of the ground to kill him you will need lots of c4 and repair nano bots , watch he comes back again after you kill him then you start again . dont forget backup fuel that can be bought in the shop on the right