I've been playing this and am halfway through the SP campaign. They got the gameplay spot on and the movement and combat feel very fluid.
As someone said earlier, the game is hard but fair, and rewards player skill much more than a typical FPS. The graphics look quite nice especially for an indie game, and the game still runs more smoothly than many big-budget releases that look worse. I especially like that shiny gold look in the energy centers. I would have liked a bit more variety in the level styling and objectives though, and most of the enemies tend to look and sound pretty similar, as opposed to the very distinctive robots in all the Descent games. There are a few exceptions like the one with the circular saws. The game is generally much closer to Descent 1/2 than 3, which is both good and bad. The weapons are clearly based on the Descent ones. The Cyclone is pretty good when you first get it but some others like the Impulse and Driller really need the upgrades to be useful. Still, it's an excellent game overall. I still have yet to play it online as well.
I got the Steam version even though I prefer GOG and their lack of DRM. The Steam one is the only way to get the soundtrack, which is outstanding and fits the game very well. I recognize snippets of the D1 music in a few places.
I still need to try out the level editor as well. I made a lot of levels for Descent 1 and 2 back in the day.