Mankind's greatest and final mistake, according to Ultrakill, was building robots literally powered by blood. Now humanity is extinct and the red stuff is running out, so the machines are plundering hell itself for more of that sweet, sweet murder-juice.

With that concept and with a big free demo, what more excuse do you need to play a twitchy arcade FPS? Released yesterday, the Ultrakill demo might have the look of an old PSX-era shooter, but it's a very modern beast under that retro facade.

Ultrakill has a Devil May Cry-inspired scoring system, speedy floor-sliding worthy of Vanquish, Titanfall or Bulletstorm, plus wall-jumping and multiple air-dashes pilfered from Doom Eternal. In another nod to nu-Doom, its health system rewards getting up close so you can literally bathe in freshly-squeezed demon blood to recharge. It's loud and aggressive, and nearly as frantic as Devil Daggers once it starts throwing whole rooms of monsters at you.

Created by solo developer Arsi "Hakita" Patala, Ultrakill will eventually be a commercial game, with plans to launch into early access sometime next year. For now, it's a lengthy and free proof-of-concept, with a tutorial stage, five regular levels, one secret level, multiple bosses and two difficulty modes. Thanks to its scoring system, it's also surprisingly replayable.

My tip to any player starting is to slide around a lot. It makes you a faster, smaller target and charges up a score multiplier. Stand still and you die, and if you're low on health, the best way to recharge is to charge straight at the nearest enemy and shotgun them in the face. Oh, and if you think the PSX aesthetic goes a bit too far (authentic vertex wobbling and all), you can tone all that down in the graphics options.

So far, my only complaint is that I can't see any option to invert my mouse Y-axis, because I'm one of those weird people who does that. Beyond that? I'm hyped for the full game - this is loud, fast, surprisingly technical shooting fun, with a gleefully daft concept.

You can grab the Ultrakill demo free, here on Itch.