Level 2 requires you to open the gate so you can move the boxes up top. But if you're serious about this I'd suggest you tackle the first Cove game first. Or play some online Sokoban to hone your warehouse maneuvers.
Sokoban (and its many variants such as the Cove games) is the greatest puzzle game ever invented. (Sorry, Tetris.) Somewhat similar to Bricks (or Klocki), it has one simple rule, you can push crates but not pull them. Out of this thousands of great puzzles, from easy to impossible, have been constructed. Any player needs a familiarity with Sokoban to complete any of the Cove games. However, you're only doing yourself a big favor by learning Sokoban.