all the worlds in the game have very dark undertones.
The worlds were destroyed by nuclear winter, pollution, world ending war (explosion), and other life-forms.
If you pay attention, you might learn the story-line.
The noise is the memories of all the horrors our protagonist has been through, remembering what each of the worlds were like before they were corrupted and destroyed, killing all the people in the universe. He realizes that he may be the only one left. With this knowledge, he eventually decides that he might as well kill himself, because nothing can save humanity from the dark corruptions it always will weave. Thus, our protagonist dives into the sun, just to rid himself of all the noise, all the trauma, all the darkness.
That is probably the darkest thing I will ever say in my life...