One Crate by Another

Here, every crate you push becomes 'locked', and you can’t push them unless you push another crate. This one is a bit smaller than the others due to level design reasons, but is still a pretty interesting one. By the way I try to fill as much as possible in each level with crates and targets, which is A LOT easier said than done. It's also known as the 'Garten of Banban' method.