So as you can imagine since i'm making this topic, I've been playing it. Here is a bit about it from the store page.
Kerbal Space Program is a multi-genre game where players create their own space program.
In KSP, you must build space-worthy craft, capable of flying your crew out into space, without killing them. At your disposal is a collection of parts, which must be assembled to create a functional ship. Each part has its own function and will affect the way a ship flies (or doesn't). So strap yourself in, and get ready to try some Rocket Science!
The game is being built first as an open sandbox. There are no objectives yet. You're free to build anything you can think of, and fly it wherever you want, even into orbit and out to other planets and moons throughout the Kerbal Solar System.
In KSP, you must build space-worthy craft, capable of flying your crew out into space, without killing them. At your disposal is a collection of parts, which must be assembled to create a functional ship. Each part has its own function and will affect the way a ship flies (or doesn't). So strap yourself in, and get ready to try some Rocket Science!
The game is being built first as an open sandbox. There are no objectives yet. You're free to build anything you can think of, and fly it wherever you want, even into orbit and out to other planets and moons throughout the Kerbal Solar System.
That is a good description of what is in the game so far. Now I only played it a few hours and was able to get the hang of the game fairly quickly. It uses real physics models and is fairly accurate in many things. This games shows why the X series would be terrible if the physics were realistic at all. The only thing truly missing is proper aerodynamic models. As of right now it is very basic with parts having a drag factor. So adding parts like nosecones to rockets is actually bad as it increases drag. Recently they added in a way to create spaceplanes, jets, land vehicles, VTOLs etc. I've only really messed with that a little bit as it is much more difficult to build a flyable, stable plane than a interplanetary rocket. It is possible to build spaceplanes that can make it to, and land on other planets though. There is an entire solar system to explore complete with a gas giant and lots of moons around each planet. All are able to be explored except of course the gas giant planet (Jool), you can send a probe in there and do some science though.
My progress so far is that I put a guy in orbit around one of Kerbin's moons (Mun) put some satellites in orbit around a few things and I just figured out how to get enough fuel into orbit to do more than just go to a nearby moon. Like I said though, this game highlights the problem with realistic physics, it is hard! I just completed my very first docking maneuver in orbit. The rendezvous wasn't that bad but it literally took 30 minutes of messing with RCS trying to dock together two supertanker sized craft full of fuel. Looks pretty though and it holds enough fuel for whatever my next long range mission will be.
There is a 4-way docking port in the center of them. You can't assemble anything in space except by docking things together. 2x tankers are now one refueling station.
Another angle showing Mun in the background:
Recommend picking this up if you are into this type of thing. I might make a short vid of some part of the game (maybe getting into orbit or something with a simple rocket) but not too much prolly unless I get really good at it and start doing some extreme missions.