Sometimes I lay awake at night and wonder what the offspring of Minecraft, Garry's Mod, and Kerbal Space Program might look like. I have finally seen it:
This title is still in early access, self-branded Alpha, available for $20. I can say it's worth every penny, and more in the realm of 'beta' than alpha.
In Space Engineers you can assemble ships and space stations from various pieces arranged in a grid-like fashion, though unlike Minecraft, there are plenty of angled pieces so that not everything looks like it came out of a Duplo set. The physics are fairly realistically Newtonian, while at the same time the game compensates for uneven thruster placement for you so you can focus on making cool-looking ships, not necessarily realistic or balanced ones.
In the creative mode, you are able to place the parts freely, much like That Other Game. This is, in my opinion, great for prototyping or making huge structures solo, but ultimately isn't what I play these sort of sandbox games for.
If you're like me and you want to feel you EARNED your creations, you can opt for a more restrictive survival mode, much like That Other Cubehappy Game. The survival mode currently is in dire need of quality of life improvements, as the large number of ingredients you need to assemble each block are difficult to fit in your personal inventory, which is limited by item volume, and it takes a bit of getting used to the fact that various parts occupy different volumes in your inventory. You only need one of the first ingredient to create a 'lattice' which then collects the pieces it needs from your inventory when you apply your welding torch to it; this allows you to start laying things out and planning without necessarily having all the pieces handy.
In survival mode you also will need to mine your own materials from asteroids. This is one of the most impressive aspects of the game, as the asteroids are handled using realtime terrain deformation as opposed to voxels, your drill wearing through it in a relatively smooth fashion.
Speaking of deformation, in both modes, collisions and damage are AMAZING. Large ships and stations in particular can have their constituent blocks dented, warped, and totally destroyed by collisions or weapons. Here's the aftermath of a highspeed collision between a ship I captured and one of the Easy Start premade large ships:
You can take your welding torch to these pieces and attempt to repair them. It's oddly satisfying watching the blocks warp back into shape, or in the case where they need pieces to be fully repaired, scrambling to find a part you can disassemble to rebuild a critical component.
You can enable random unmanned ships which will cruise through your sector, and with a bit of careful flying, you can dock with them and board them, taking them for your own to be torn apart or modified for your own purposes. Be careful, though, as most of them carry some defenses, such as chainguns or missile launchers, and will quickly destroy any light spacecraft.
Now for the bad: The world is limited, not all those asteroids you see in the background are accessible, they are just part of the skybox; in the starting world I'm in there are maybe 4 or 5 actual asteroids, but honestly that's not a big deal. The world is approximately 30 kilometers to each side. Additionally, there's no dedicated server yet, but there is one in the works. I haven't had a chance to test the multiplayer functionality myself, but it does exist, and seems to be fairly fleshed out.
I hope this has given you a bit of an idea of what to expect from Space Engineers. I considered it very much worth the modest price, and would highly encourage anyone interested in sandbox and building games to grab a copy.