Here is my 100% Achievement guide for Hardcube!
This is the last missable achievement to get. (Although there are many lasers that can kill you throughout the 4th levels).
But when you start level 4-1, go round a little bit and you see a laser with a red tracker going left to right.
Usually of course you want to avoid it, but go straight into the red tracker, wait literally less than half a second, laser hits you, achievement unlocks.!
Go to 18:45 to see where and how i unlock this
Hope This Helps!