Achievement question

[Nemonical-Yves]

Hello there, after many attempts at this brain melting experience, I still don't have any idea what I should be doing for the "Brain Bait" achievement. Can anyone help me out here?

Also, there is one secret achievement I don't have so far, it's called "Defuse all" or something like that. Am I right to assume that I must purge all enemies from the screen for that? If that's not it, what do I have to do?

Edit: "Defuse all" was exactly what I thought, I managed to clear the screen of enemies and got it. Still no clue what "Brain Bait" is about.

Edit 2: turns out pressing Z after starting the game does the trick for "Brain Bait".