Overview
There are two ways to climb.
Climb #1
You can climb by putting both hands on the top of the edge on the block. Look down to pull yourself up. That’s the easier way. The harder way…
Climb #2
Where were we? Oh, sorry. The harder way… Jump and grab the block with one hand and sway your body by pressing A and D. Then grab on with your other arm. Keep trying it over and over. It’s pretty helpful while trying to earn Thief in Power Plant and Top The Hat (the least common achievement) in lobby level Christmas.