Please help me figure out the meaning of the phrase "slid down tubes" in the following sentence from the description of the game "Minion Rush":
For six and a half harrowing minutes, we ran up ramps and slid down tubes, steered around boxes and into hapless bystanders, until we hit a surfboard that refused to budge. (Apple's App Store)
I got a reference to the word "tubes" here:
While you run, you encounter a series of obstacles, from a range of metal rockets to glass transportation tubes for the minions. (Venture Beat)
I am still not sure about the meaning of the phrase "slid down tubes".