Its not a direct sequel, these are totally different stories. Play them both, theyre about just as good.
and combo spoiler below, if you need help.
Putting enemies to sleep allows you to feel their heartbeat. this is the rhythm at which you want to press th button once the combo gets started. when to first press the button to get over 2 hits is still a mystery to me. And yes, each rythm is dependent on background music. one good way to practice on emulator is to save state when the window "Flint attacks." comes up, try to get a combo, and then load state every time you screw up. you can do that for every attack, but in the end its a waste of time and takes away from the value of the game.
my highest combo is 13, pretty sweet. The fluctuating speed of emulators really throws it off though