The levels end when you reach their A+ score goal, but before that it doesn't tell you how much is needed for it in any way, other than what we can perceive as "the majority of objects found in the level".

So this quick guide was built with this in mind, providing every A+ score needed for each level, thus enabling you to better plan your route through them. This should help you decide if a run-for-it moment for a cluster of objects far away will be enough at the last seconds.

Grades are only obtainable on Timed Mode.

Getting A+ ranks on all levels will net you the Wonderful Grandmaster achievement.

There we go. If this guide has helped you out, don't forget to rate it. And if there is any way that I can make it clearer, do comment.