Thanks for playing! Apologies for the tutorial part, it was one of the last things we did so it was kind of hastily thrown together.
To clarify, the idea is that any attacks you perform will spin the tape spool forward and consume tape in the process. If you time your attack to the beat, it will spin forward by 1 slot and record your attack to the tape. If you mistime it, it will spin forward by 2 slots and you'll lose double the tape. If you don't have any tape at all, you won't be able to attack at all.
To recover tape, you can manually spin the tape backwards by pressing E (or RT on the controller, which is the control scheme I'd recommend). If timed to the beat, this will get rid of any stored notes you have and get you some tape back. Otherwise, you'll just lose two slots worth of tape. Parrying spins the tape back and gives you tape as well, with none of the drawbacks.
If you perform 4 successfully timed attacks in any of the sequences listed on the top-left corner of the screen, you can press F (or LT) to get a unique discharge buff. It'll consume all of your tape but you can cash out on a lot of damage, heal yourself, or tank a hit. Pressing SHIFT will let you dash without any consequences. If you time it to the beat though it'll make a sound.