In single-player, select the Skill Game Circus and then choose the UFO challenge.
The challenge has you piloting a UFO, landing on markers scattered throughout the map. Ignore the markers entirely and fly to the far right of the map. You should eventually reach a large building with an open chimney at the top. This is located to the right of the final landing point.
Atop the chimney is a light that turns red and causes instant death after 36 seconds, so you need to get there before it turns red. If it's safe to enter, the light will be green.
Carefully float down the chimney and you'll reach a maze. Pilot the UFO through the maze without crashing and at the end you find a small platform to land on. Land on it and the achievement is yours after a few seconds and some fireworks.
Some tips:
1) Flutter the accelerator, never floor it. The UFO is aligned poorly and will tip to the right, so you need to keep adjusting your angle to remain straight. Fluttering the accelerator makes this much easier and will prevent crashing.
2) Take your time! There's no time limit you have to worry about once you get inside the chimney, past the red light. It's just a matter of being patient and not rushing. Very doable on your first try if you're careful, but it's a good idea to familiarize yourself with how the UFO handles before entering the maze.
[UPDATE: Thanks to those that pointed out about the light atop the chimney. Never ran into this issue myself, and you shouldn't either, so long as you go immediately to the chimney once the challenge starts.]