The level's difficulty probably comes from the fact that it is supposed to guard the central part of the Omegamatic against intruders, as the name implies. This is the first level to feature a closed security door that requires a keycard.
You begin by running left toward a yellow pole between two vertically moving Slicestars. Slide down this pole. To your right, there is a hidden passage with extra points. Run back out and keep going until you encounter a second pole. This pole leads up to a platform upon which you will find a switch. This switch opens a bridge further on.
Drop down off the platform, being aware of the Sparky below. Run further left until you reach a third pole. Climb up this pole. Upon reaching the top, jump off to the right. There is a red key. Hop up onto the platform to the right. Keep running until you reach a break which leads to another platform. Hop over to this other platform (do not drop down), keeping aware of the sparky and Little Ampton there. Run to the red keyholder, then climb up the pole immediately to your left. (On hard, watch out for the laser on the ceiling.) Jump into the opened room, which holds a blue key.
Return to the place where you found the red key. Spring up and to the left onto the green platform. Jump up to the pole above. Hop off onto the nearby slanted ledge, then run to the blue keyholder. Continue right until you reach the two holes in the ground. Jump up onto the first platform to pass over. Ride it off to the left, being careful not to hit any of the fire helices along its path. You should reach a ledge on the far left of the room. Jump onto this ledge. Run into the room on the ledge. Grab the keycard. (On hard, try and jump over the horizontally moving Slicestar.)
Once you have the keycard, drop back down onto the main floor. Run back to the two holes. To drop through, hold the "down" key and press the "jump" key. The one on the left leads to goodies but nothing necessary. After dropping into this one, hop back up, then drop into the one on the left. Flip the switch, then run right. Wait for the platform to be within jumping distance. Get on, and ride it up. As soon as you reach the top, jump onto the ledge to your left. Run left, being careful of Slicestars and the Sparky. Beyond that, carefully jump through the energy beams. Do not touch them while fully lit. (Alternatively, there is a hidden passage that will take you over the energy beams, just before you reach them.)
Continue left until you reach a door. Enter this door. Go right, being wary of the Sparkies and multiple lasers on the ceiling. (Depending on difficulty level, anywhere from zero to four of these will be firing.) Go further right, until you reach another door. Go through the door. In the last room, there will be up to three Sparkies. Dispatch them, and continue to the exit door.
There are no less than 226,600 points in this level, but due to a tilemap error, Keen may not reach a total of 16,000 points without cheating, ending the level with a nonetheless impressive 210,600 points. This is the most points found in any level in the entire Keen series, more even than in the secret level for Keen 5, and in any case a huge sum for such an early level in the game. It should be 42 Shikadi Gums, 57 Marshmallows, 42 Chocolate Milks, 28 Tart Stixes, 11 (8) Sugar Stoopies Cereals and 28 (26) Bags O' Sugar, in other words: 4,200 + 11,400 + 21,000 + 28,000 + 22,000 (16,000) + 140,000 (130,000) = 226,600 (210,600). There are no jars or Vitalin to be found. The two Kegs O' Vitalin remain accessible.