You die in one hit, but you've got a decent arsenal of moves to feel like a badass: You can:

• Defend: Dodge dash, block, reflect bullets, parry melee attacks
• Use your katana: usual melee swing, AoE spinning strike
• Do fancy special moves from time to time: long range dash that slices everyone in your way, ultimate ability that kills everyone on screen.
• Use firearms while you're out of stamina.

You need to manage your stamina, keep in mind that ammo is limited but regenerates over time and try to keep the combo going by killing somebody every 2 seconds, but all of this while not getting hit.
There are also special enemies that require special treatment.

There are challenges in this game that unlock new gear and vary your playstyle a bit.

But overall it's just an arcade game: short play sessions, but you'll replay again and again because the gameplay itself is fun and not because you want to progress the story or unlock something.