If you take one thing away from ReBlade, make it this: the parry is the whole game. Everything else - weapons, chips, augments - exists to make the parry window easier to hit or more rewarding to hit.
Parry (弹反, also written 拼刀) triggers on a well-timed input and is the only way to fully negate damage. Two details make it far more approachable than a FromSoft parry: the input has a high priority, so a slightly early press still connects, and a failed parry degrades to a damage-reducing block rather than a clean hit. You will not die for being a frame early. The dodge button exists, but it is secondary to the parry in every fight.
Enemies flash white before an attack. That white flash is your parry cue. The shield/poise bar underneath is what you are actually trying to drain: precise parries chip it away, and when it hits zero the enemy is left wide open for an execution or cyber-body finisher.
This is the demo's most satisfying technique and most players never find it. Deflected blaster and plasma rounds do not vanish - they fly back into the surrounding enemies. Explosive projectiles can be kicked back at staggered foes for free damage. If a group of gunmen is shooting you from across the room, standing still and deflecting their fire back into them is often faster and safer than closing the distance.
Each successful parry builds a suppressed state on the enemy that doubles incoming damage. This is the intended aggressive-parry payoff described in the Japanese and Chinese hands-on coverage - the game wants you to stand in front of the blade, not behind it. Practically, that means parrying greedily rather than parrying defensively: every connected parry is damage stored up.
Red or glowing attacks cannot be parried - attempting it takes the full damage plus the stagger. Identify them in the first two layers of the demo and treat them as hard dodge cues.
Learn on trash mobs, not on a boss. The first room of the demo is enough to teach the rhythm: parry, counter with a combo, finish with a heavy. Only once the parry connects on a routine basis should you take that rhythm into an elite room. Remember that the demo grants extra lives and multiple difficulty tiers - use Normal and the spare lives to learn the two layers before the full release.