Ugh, I think you can describe how I progressed in this video with a negative slope graph. It seems like the farther I went into the world, the worse I did. I had to use a bunch of items as well. Items that I was hoping to save for World 8. If you think my performance was very bad here/think that some of the levels up to this point were tough, then you haven't seen anything yet. World 8 is THE most unfair world in the game, no doubt, but it does house a couple of my favorite stages, so that's a plus that makes going through some of the more unforgiving stages worthwhile.