Yes, Destiny/Zack0Wack0 made it a while ago
I'm not sure how the guiding worked
i'm not sure how making it immune to explosives would work but it may be achieveable by using insane mass settings
Oh, the guiding worked by something close to zonebricks. There was 3 bricks it used, Start Brick, Track Bricks, And End Brick.
They would glide along the track bricks, though they were oversized and ugly (they looked like vehical spawns)
Obviously, once it reached the end brick the game ended/reseted