The progress reflects the characters

Zero - Above and beyond, all crystals and gems, plus 99 lives, got the true ending like a professional hero

Zera - Stopped the villain, but failed to go the extra mile, though she still went out of her way and collected the colorful gems 

Cryos - Not on the side of good, ignored every gem in favor of getting the bad ending 

RatCat - You can figure it out