World 4 - Level 2
Collect the bonus coins hidden in the two houses, then collapse the yellow "X" and start building a bridge north at that point using the two circles powder kegs. Now move the wood box along the red path, make sure to separate the two Kaboom!s at the house corner. Follow the first Kaboom!, when it detonates at the powder kegs, circle around the left house counter-clockwise to retrieve the purple powder keg. Use it and the wood box to complete the bridge.
Traverse the bridge using the indicated path. This will allow you to retrieve the box marked in a yellow circle. Collapse the bridge at the yellow "X" by stepping on and off, then fill the hole with the wood box. You can now collect the upper-left coins. To collect the upper-right coins, use the fake wall marked in green to collect one coin (and only one coin), then the rest using the wooden bridge.