The most replayable demo in Steam Next Fest is Ghostrunner 2 and it's not even close

gamesradar.com:

God, Ghostrunner was good. I'd almost forgotten how good until I loaded up the Steam Next Fest demo for Ghostrunner 2, which is just Ghostrunner but with a 2 on the end. It's got some new tricks, but it's the same exhilarating first-person action romp under the hood, and I wouldn't have it any other way.

Act surprised: Ghostrunner 2 absolutely whips. It's one of the best Steam Next Fest demos you can play, and it's hands-down the most replayable trial in the whole event. Even without the hidden collectibles and end-of-run scoring system, I would (and indeed will) happily blast through this demo multiple times just to get my heart rate up. I'm always looking to squeeze in some easy cardio, and nothing gets the blood pumping like a breakneck sprint through this familiar cyberpunk playground. 

Aptly named developer One More Level once again nails the frenetic pacing of puzzle-like encounters where you chain together the most absurd stunts and executions you can imagine. You bounce around like a Beyblade in a blender, chucking shurikens, swinging your katana, parrying incoming fire, slowing time, dashing mid-air. It's cyberpunk Doom Eternal by way of Katana Zero. Push a dude back with telekinesis, grapple onto his flailing body, courteously escort him into the afterlife, grapple up a nearby ledge, pop slow motion and chuck a shuriken at a bomb as you fly by to paper the walls with three other dudes. Chef's kiss. 

Everything dies in one hit, including you, which gives Ghostrunner and now Ghostrunner 2 a Super Meat Boy-like flow of constant, instantaneous game overs. But checkpoints are so frequent and easily reloaded that it never gets frustrating. Ghostrunner's visual language is phenomenal and the cause of your death is