With some moderate exceptions, most of Super Mario Bros 3 is pretty easy, especially if you’ve accumulated extra lives in the many easy ways the game gives you. Anyone who was able to win either of the first two games no doubt walked through this one with ease. That is until they got to World 8.
The design of level 8-2 is not terribly complicated, especially compared to the airships and the dungeons you’ll be visiting. There aren’t many enemies other than some Venus Fire Traps. As you can see, there are some bouncy musical notes you have to jump across. But Mario has done that as early as World 1.
And then this fucker shows up.
Later I learned you can skip most of this level (along with the melodic pit of death) by falling down some quicksand near the beginning. Until then, this moment was one of the greatest challenges between me and sloppy seconds with Princess Peach.
Death By Troggles 
Absolutely hated the sun when I was a kid. I could never just be patient, and wait for him, so I kept trying to outrun him, which always caused me to fall into a pit or quicksand. Now I just koopa shell the bastard!
Likewise
I never had trouble with the sun, but I learned early on that this was abnormal. This is the worst level in which he appears, though, certainly.