Tips & strategy
Never push a crate into a corner unless a target is there. A crate in a corner can never be moved again, because you cannot pull and you cannot get behind it. Recognising dead squares before you push is the core skill of this puzzle.
Be careful with crates against walls too. A crate pushed flat against a wall can only slide along that wall, so if there is no target on that wall, it is as good as lost. Check the wall line before committing to the push.
Work out the order of crates before you move anything. Often one crate must reach its target last because it blocks the path you need for the others. Solving the sequence on paper, or in your head, saves far more time than trial and error.
Think about where you need to stand. Because you push rather than pull, reaching the far side of a crate may require a long detour, and sometimes that route is blocked by another crate you have already placed. Plan your own path as carefully as the crates'.