What are the differences between Normal and Hard in Sonic Forces?

According to a thread on GameFAQs:

Normal means you don't lose all your Rings when getting hit, but as a result you can only have 100 at a time.

Also:

I think you only lose 20 rings at a time in Normal Mode, as apposed to all of them in Hard Mode.

It seems like normal changes the regular ring system to work more like a health system, so each time you collide with something that causes damage to sonic you will still lose rings, but not every single one. It caps at 20 but not entirely confirmed by the person who said that as he only says 'I think'

As someone that used to play a lot of sonic I would recommend playing hard mode, would be a lot more enjoyable imo.