I came back to three star all the levels Jackscepticeye couldn't three star in his first go.
To beat level 27:
Go into the small hole in the wall near where you spawn
As soon as he drops down past you, run behind him
Rush to stand behind the last green coin as soon as possible, so that when the plumber jumps to get it, you will kill him
Hope this helps!
Level 27 is terrible. I would like to see the game designers beat it.
It's a fun game; but it's too hard.