Before Counter-Strike won the Mod War (1996-2003), it was common for total conversions to take cues from John Woo films. Mods like Action Quake 2 (and its Action * derivatives), The Opera and The Specialists made multiplayer that wasn't simply about running and shooting, but about doing both in style, preferably by diving sideways in slow motion through a skyscraper window while idly daydreaming about how good the Matrix sequels were surely going to be.
Those days may live again (even the Matrix bit, if you still dare to dream): some of the makers of the Specialists have released a free, standalone multiplayer shooter called Double Action: Boogaloo. Free as in free, that is; no microtransactions or free-to-play infrastructure, just a simple game of wielding pistols akimbo and releasing flocks of doves. There's a new trailer and more detail below.
This is a neat bit of editing:
If you want more traditional mod style, here's a longer game trailer scored by some iffy remixed music:
Double Action first popped up as a Kickstarter project last April, when a two-person team had been working on it for two years and wanted to devote their full-time attention so it could be finished that summer. This obviously didn't work out, as the project fell far short of its target. Still, the developers had level-headed ambition: the game was always going to be free, they had no interest in stretch goals, and they were upfront about the fact the game would never match megabucks production levels. That may have hurt their Kickstarter prospects, but it's probably the same qualities that have seen the game released now.
The latest version of DA:B is downloadable now via ModDB, and all it requires to run is that (the free) Source SDK Base 2013 Multiplayer is installed within Steam. If you don't have that already, the Double Action installer will prompt you to download it automatically.
I've had a quick mess around with it and its simple window-smashing dives are certainly satisfying, but at time of writing the servers are empty. This means that you - yes, specifically you - are the secret ingredient still missing from the game.
Once installed Double Action will appear and can be launched via your Steam games list, but if you'd like to be able to download it directly through Steam, the game is is looking for votes on Greenlight. There's more trailers and screenshots there, too.