Sand Yego consists of some kind of fortress made out of earth and rocks. Though in the world map thumbnail it appears to be a more complex building, inside the level it can be seen that the fortress is merged with its environment. It has two "sides" (a front and a back), consisting of two earth towers, with several tunnels between them. There is also an underwater pool that can't be reached.
Keen has to find his way through the tunnels, getting the green gem and turning on some moving platforms and bridges, to eventually reach the exit. The level is hazardous in that it has a lot of Mimrocks and Arachnuts. There are also Poison Slugs, Mad Mushrooms and Skypests.
Sand Yego contains a small secret area in the first side, on a floating chunk of earth, which contains an extra life. To reach it, Keen must find some small invisible bricks, which can only be seen flashing from time to time.
This level has 56,900 points in total. That means 50 Shikadi Sodas, 27 Three-Tooth Gums, 29 Shikkers Candy Bars, and 4 of Jawbreakers, Doughnuts and Ice Cream Cones alike (5,000 + 5,400 + 14,500 + 4,000 + 8,000 + 20,000 = 56,900). There are quite a lot of drops: 79 in total. There is one Lifewater Flask in the place already mentioned.
See also List of Keen 4 Levels.