I finished it, but still playing it. Totally recommended. It's a mixture of third person slasher, bullet-hell, platformer/shoot-em-up, though most of the time you'll be in third person slasher mode. Great graphics, oozes style, good music, even though I'm not into twitchy games I somehow managed to finish this on normal difficulty. I played it in my PS4 so don't know how K+M handles.
When you finish the game, you get to play again with a different character, but not in the typical way. In this game, say in one hypothetical scene you and your companion need to kill a giant robot boss, you both go at it but it's too strong, your companion says something like "Wait, I see a hatch in its leg, I'll go check it out" he leaves you and a minute or so later he tells you in the com 'Ok, I disabled the knee, he won't be able to move, finish it!' and you go and kill it. In the second play you play as your companion, and instead of attacking the boss you play the part of going into the hatch and disabling the knee (with a different set of challenges). Also, all the conversations you two had you're now in the other side, so you get to see the companion's thoughts. So it's a good and fun way of replaying it, not to mention it's much faster because you keep your 'addons' which makes battles faster (and you don't spend time with the side-quests).
EDIT: Never mind! I didn't finish the game even though the game implied I did. You really do need to continue playing, the story goes on! The first credits scrolling is basically like halfway through the game.