Tales from Space: About a Blob

There are four types of cups obtainable; Bronze, Silver, Gold, and Platinum. You can highlight each level from the 'Story Mode' menu to see what cup and percentage you have for that level so far (including how many Blob friends and collectible points you have). You can use level select after finishing a level to go back and try working towards 100%.

What's included in that percentage is collecting all the collectible points and absorbing all of the Blob Friends. Beating the target time for the checkered flag is not part of the percentage, or this trophy.

When you're retrying a level, collectible points and friends you have already gotten will be grayed out; while those you have yet to collect will be colorful.

For a Gold cup, work for 85% or better on a single level.
For a Platinum cup, work for 100% on a single level.
For this Platinum Blob trophy, you will have to earn a platinum cup for each individual level, the same applies for Silver Blob and Golden Blob trophies.

If you're having difficulty collecting any collectible points as it seeming too unreachable with your current size, try going further and absorbing more objects with to grow in size. Once you've grown a bit more, head back to the previous spot you were having difficulty with and see if you can now reach it. While following this tip, make sure you're able to get back to where you were originally (for example, don't fall down into a hole if you're not able to get back up).

Another alternative for getting collectible points that seem unreachable: try jumping with then pressing to quickly hit the ground then jump again in quick succession to help boost your jump higher in the air!