There is no better representation of this game's dual nature than the control scheme at the title screen. Mystifying and annoying at equal proportion, the game tells you to move through menus with the arrow keys but select them by clicking the mouse. This alone should have tipped me that the minds behind Killer Is Dead were not normal and that I was going to enjoy the weirdness, but it would also get in the way.
At the heard of it all, KiD is a button smasher hack 'n' slash. You play as Mondo (a stupid name unless you realize that "Mond" means "Moon" in German), a guy with a katana and some kind of bio-mechanical arm that turns into different weapons, and blindly blast through different areas of henchmen until you fight a boss --pretty standard stuff. The combat is fine as far as it goes with a fine balance between mindless button smashing and dodging and blocking at the right time to trigger special moves. Shooting with your left arm (and fixed turrets) is by far the weakest element but also is heavily emphasized; there are numerous encounters which require you to shoot the baddies.
Judged merely by it's core gameplay, KiD would stand from the crowd, but it shines in it's bizarre presentation. I'm a sucker for the cell-shaded aesthetic so that's already a plus. But adding to that, colours are often distorted as if looking at a crappy laptop screen from a high angle. The sound design is purposely atonal at times and meant to confuse you. On top of that, the story is just nonsense. And I don't mean that is strangely told or difficult to interpret. No, I mean complete and utter dream-like nonsense. This is a world in which mechanical bodyparts exist, but also the Moon is somehow evil, and you meet a talking unicorn, and there's vampires... Dialogue often makes no sense as if characters where each in their own little parallel story and the game keeps throwing the most bizarre contrivances to the point that you need to make a choice: you either quit the game in disbelief or you stop caring and let the weirdness wash over you.
I chose the second and I stand by my decision.
While the art style is undoubtedly the game's greatest strength, it often gets in the way of the gameplay. The strange colours and high contrast often makes it hard to see where you're going and the colourful puffs of smoke in which enemies disappear when killed sometimes obscure the action.
Of course, it wouldn't be a strange Japanese title without some disgusting sexual elements. First, your sidekick is a nominally 20 year-old girl that talks, behaves and once is referred to as a child and who you can change into skimpy costumes. But since the developer doesn't seem to think this is gross enough, there are also several side missions in which you "date" (heavy emphasis on those quotes, readers) different women. These consists on you staring at their boobs to fill your "gut" meter until you feel brave enough to give her a gift that fills yet another bar. Not only it's distasteful, but also plane boring and only subtracts from the experience. Luckily, those "gigolo" missions are optional.
If you like to play something short, not so challenging and essentially nonsensical, I recommend it.