I hate working on two hacks at once, but fortunately it usually happens when I'm almost done with one of them.
The basic idea is that you have to wait for the mole to fall partly down, and then scroll the screen to the right and quickly jump over the gap, making sure the mole goes offscreen before the disco Koopa kills it, and then at some point respawn the mole and ride it underneath the invisible noteblocks to the next area. Whoops, I just realized this screenshot is impossible because the mole falls down before you can get up.
You might not be able to see it clearly, but the stars spell out the initials of this hack's name. This is also one of the latter areas of the level. And this part is autoscrolling. This area plays some Phoenix Wright music.
This is the part that plays the aforementioned scary sounding music. And no, you're not required to use the Hammer Brother/lava glitch. You're gonna have to do something more crazy than that here, and it involves the berry.
Huh? Where did that fish come from?
Legacy custom music
A site with a non-useless dislike button
SMW hacking channel