TURN THE LIGHTS OFF INSIDE THE CYCLOPS when operating it. It's good to practice this before you go down. For close quarters, you'll almost ram it into an opposing wall before you turn. Your turn axis isn't what you'd expect unless you've driven something large before: the turn axis is pretty far back so if you want to make a certain turn, you have to over-drive-the-turn (e.g., you will drive past where you want to turn, then turn: you have to get the center of the cyclops lined up and you're way in front of it).
Operating it is kinda simple and it's sorta like driving a bus. You build them in the deployables section of the fabricator (not the cyclops fabricator, so you have to build one in the cyclops if you want to make them on the go). Decoy blueprints come from Pod4, which is on the surface port-side of the Aurora (near where you enter it).
