Need help with Chapter 30

Hello, I need help with Chapter 30. It seems like I've been on it for months. I have 2 undamaged ships and 1 cannonball, but I just can't seem to complete it before time runs out. Is there something tricky I should be doing? Thanks.

As each power up in the lower right corner becomes available, use it immediately, especially the Hourglass. The power ups do not get stronger or accumulate more power if you let them sit unused as in some other games. If the Army and Hourglass power ups are both ready to use, always click on the Hourglass first and empty it to the time rope. Then click on the Army, as the Army will clear some hourglass tiles and send them to the now empty hourglass power up space. Maybe this will help you have more time.