In "A Road to Nowhere," find all four diamonds. The same solution applies to this and the last game.
The first diamond is a second pillar with the spikes and a ladder on one side. Climb up and then jump the platforms.
The second diamond is right after the first flower the treadmill will go below a platform. On the other side, spin to destroy the boxes and reveal a jump pad. Go to the right for the diamond.
The third diamond is from the checkpoint, rather than following the main path, go left to find a jump pad, then go right and jump over the spikes.
For the fourth and final diamond, continue the path until you see a bee on a higher platform on the left side of the path. Let the platforms switch until you get a jump pad next to the bee's platform. Jump and dodge the bee. Achievement/trophy for A "Diamond" Dozen pops when you pick up the last diamond, same thing goes for the Diamond Dog achievement in the previous game as well.