I have this weird bug where sometimes the light speed dash works perfectly and sometimes it doesn't respond at all I only ever play on an xbox controller and havent tested keyboard and I find it a little frusturating but overall its a fantastic game. 

Edit: there are problems I forgot because I was so invested the rails are kinda wonky and sometimes fling me off or miss the homing attack also my rings reset when I switch characters and it stays at 0 when switching back. 

About the rings. When you change your characters all your rings will go to the saved rings section to buy the emeralds.
To do the lightspeed dash properly you must leave the button pressed. if you release it the lightspeed dash will end.