Hardest achievement in Run 3 *POLL*

In Run 3, 92 achievements are published. Some of them are easy peasy, while others are crazy hard. We have decided to make a poll for the hardest achievement in the game. It will reset approximately every half year*, and please do not vote until you can interpret what each of these achievements are and have earned all of them. (And feel free to recommend an achievement if you have an idea in the comments section below.)
Warning: Don't add any new achievement or edit the poll until the next reset because it will reset all votes to 0.
Next poll reset: 1/1/2019
<poll>
What is the hardest achievement in Run 3?
"Unlimited Endurance"
"Figure Skater"
"We Will Survive"
"Widdershins"
"Bunny Hop"
"What's Inside?"
"Landlubber"
"Angled Surface Enthusiast"
"A True Engineer"
 </poll>
If you have any achievement ideas for next time's poll, put them here.
Achievement 	Your Name
Watch Your Antannae!	Haycat2009
Category:RfC