de Blob

This achievement requires you to get a gold medal on each level's main story mission. You get a gold medal for having a specific number of points for each level. Completing every task within a level (challenges, buildings, landmarks, etc.) is an easy way to amass a large number of points and will likely come naturally if you are going for Da Vinci, Braveheart, and Transformers.

An to garner extra points would be painting blocks as many different colors as possible (max of 7) to get a bigger bonus and some of the challenges have you complete blocks anyway thus giving even more points. You can press Y to use the compass to find the remaining challenges and unpainted areas pretty easily. Use this as your in-game guide until you get your gold medals.

NOTE: For Ministry of Ink and Lake Raydia, there are points of no return at which point you will be unable to backtrack to previous parts of the level. These points of no return are right before you get onto the long ramping downwards bridge , and right before you get onto the ship (and before you enter the area of the final boss fight). For Ministry, assuming you are doing everything, you should be at 88% as you pass the bridge and should already have the gold medal. You CANNOT use the compass to find the last areas to paint for this level.

Lake Raydia is a bit trickier. Painting everything prior to the ship will give you just enough points for a gold medal: 150,000. However, one advantage of this level is that you can use the compass to find all of the remaining areas to paint if you beat all of the challenges before the ship. The ship itself also provides tons of points for you there, so if you don't have the gold medal by then, just keep painting until you do.