Score charts without Time Over can be potentially broken. For example, I left my DS on overnight on Sweet Mountain 1 so that Sonic would continually collect the same respawning Wisp for 10 hours. This yielded a ridiculous score in the 500,000s (mod 1 million; there's only 6 digits in the score display). To prevent things like this happening, Time Over should be a requirement for Score charts like it already is on Ring charts.