This particular time achievement is much easier than the previous level's target. Level 2:1 goes back to being a lot more horizontal and there isn't really that many different platforms to explore, vertically. A shield powerup should be available to pickup which you can use to prevent taking damage from any enemies.
The level is really straight forward to make it through quickly while focusing solely on saving the red puttys. Here's another video showcasing a successful attempt at nailing a better time than 1:15.