How the hell do you turn on power?

It says there's a nightmare mode and an easy mode, but there's no way to select those options on the map load up?

So on the Fortress map made by fearxreaper (I believe) and whenever I pick up a gobblegum, it finds a "cheat detected : noclip" when I don't have any on. Is there anyone that can help me with this?

Where are the UGX Mod options?