The fact that you can "air jump" right after you rewind to the time you placed a block, making possible to reach any place with only one block, is a bug, isn't it?
It was kinda hard until I got Psionic Wistle (or something like that). The kitty was always falling into some place that I coudn't reach, so I had to commit suicide. Nevertheless, good game.
First you need to wait for the spinning thing to hit the frozen vikings. Then when the right most one is swinging in the direction of the boat, cut the rope, so he falls on the boat. Repeat for the other two vikings.