|N version||1.3 and later|
This level's "partner" is level 59-3. It is called "stalag tight", and features a similar tileset and enemies - the main difference is that the rocks in 51-3 are wide, not tall. Another way of putting it is that it uses tile 3, not tile 2 in the NED interface.
From the start, jump to the rock to your left, then leap to the terminal, and land on the rock to the left. Jump, and drop down onto the first switch, and land onto the right-facing sloped rock. Leap to the rock to the right, then jump to the second switch and land on the right-facing slope rock below. Drop down and land on the left facing slope rock near the third switch, then jump to the switch and land on the rock to the left. Leap over to the rock near the exit, then drop down into the exit tunnel and exit the level. This is one way of doing things, but this level has loads of possible routes.