Gave this a go and the concept is really cool. However, I didn't even get to the combat part yet, and I think this really won't be everyone's cup of tea. If I hadn't played KSP for hours, I think I'd have had a lot of trouble simply getting to an asteroid or space station.
Stuff takes a decent amount of time and there's a learning curve there, which is laughable for DF players but probably a bit too much for most people.
There's also some UI and small issues that can annoy you, like accidentally clicking somewhere while grabbing an asteroid and not noticing you've just set up a waypoint and your ships is automatically making some random burn that will either throw you towards the sun or inside the atmosphere. Then again, I went straight into non-sandbox mode, so I kinda asked for it
Still, it's fun flying around and upgrading your ship little by little. Things like poor thruster placement will make your life harder, and it got that Space Engineers feel of having to think about the logistics and systems with your design. In order for a simple Fuel Refinery to work, for instance, you
need to define an Ice/Power Input, and Hydrogen/Oxygen Output.
You can connect the modules yourself or let it autoconnect, which I find pretty nice.
I'll follow its development for now on. And to be honest, the price tag makes it a great deal.