The Pentagon on Strings is the 3rd member of the String Obstacle class. It is only found in Checkpoint 8 and Zen Mode. This shape is one of the easier obstacles to destroy, the hardest one being the Painting in its class. It is colored red in Checkpoint 8, black in Zen Mode. You only need the Explosive Balls Power Up to destroy it in 1 shot. These things do absolutely nothing thanks to the strings holding them, but they may be in your way, so shoot at them just in case.