Sub Zero

Sub Zero is the fifth episode/circuit in Angry Birds Go! It was added with the March 2014 update on the game.

Info
The episode was announced on the Angry Birds Facebook page:

Things are about to get really frosty in Angry Birds Go! We have a free new episode coming soon, so stay tuned! http://rov.io/downloadabgo

Break out the ice scrapers and start your engines! Angry Birds Go! v1.2.0 is now available for iOS and Android, and brings loads of new content!

This update includes:

The new Sub Zero episode! Speed your way along the snowy and icy terrain in the arctic battle of snowmobiles. There are 18 races to win.

Features

 * Seasonal event tweaks! There is no “boss” in this episode, but rather a difficult Slalom race, where you must coordinate your way through the gates like an Olympic athlete! Also, “Fruit Splat” has been replaced with “Ice Splat”.
 * Loads of new carts! There’s only one cart available for coins (Tar Barreller L1 for 2,000 coins), several available for gems, several available by TELEPOD, and a one available as a $1.99 IAP (with a bonus of coins and gems).
 * New Daily Event to earn some extra coins and gems! Compete in this event daily to increase your reward: Day 1 is 200 coins, day 2 is 400 coins, day 3 is 8 gems, day 4 is 600 coins, day 5 is 16 gems, day 6 is 1000 coins, and day 7 is 20 gems. Also, you can connect to Facebook and double the reward! Note that the event seems to run 1AM to 1AM Eastern Time (10PM Pacific).
 * Dozens of miscellaneous tweaks, bug squashes, etc. Notable among these are a display of all opponent CC’s at the race start, squashing some impossible-to-beat challenges, and more!

Karts

 * Bomb's karts
 * 1) Tar Barreller (Level 1)
 * 2) Polar Ice Cup (Level 2)
 * 3) Cramp-on Crawler (Level 3)
 * 4) Tracked Trekker (Level 4)
 * 5) Snow Shoo (Level 6)
 * King Pig's karts
 * 1) Slushy Slider (Level 1)
 * 2) Snow Scoop (Level 2)
 * 3) Sledge Hog (Level 3)
 * 4) Strike Out (Level 4)
 * 5) Shred Sled (Level 6)
 * Chuck's karts
 * 1) Chuck Ice (Level 6)
 * 2) The Blue Cornet (Level 6)
 * Terence's karts
 * 1) Mr Plow (Level 6)
 * 2) Arctic Roller (Level 6)

Trivia

 * There are Telepods for this episode/circuit.
 * This is the first episode in an update on Angry Birds Go!
 * It is the only track not to include Champion chase.
 * Since this episode is only a preview, it is also the shortest episode in the game, featuring only one track. However, there will be at least 1 or 2 updates for this track later on.