While it's touched down in alpha form, you can read our Kerbal Space Program review to see if it's worth your buck.
Space trivia fun-time Friday fact! Did you know? Actual professional scientists in the 1950s designed an alternative to rocket engines in which a ship would be launched by repeatedly exploding atomic bombs beneath it and surfing the blastwave into space. Which was clearly silly because we've all seen Star Trek and that's not the solution to spaceflight we ended up with.
For many obvious and varied reasons, the project never progressed past the testing phase, but thanks to a Kerbal Space Program mod we can see what such a terrifying machine might have looked like. The answer? Terrifying!
Weirdly enough, it wasn't the clear danger of wiping out the human race by filling our atmosphere with radioactive fallout that cause the project to be shelved. Rather it was partly because the spaceship design was so efficient that the US government couldn't think of anything big enough that they'd ever need to put into space, and so they stuck with smaller, safer, regular rockets.
Here's regular Kerbal Space Program YouTuber Scott Manley testing out the ship design, which is nothing if not noisy.
The mod can be downloaded from the Kerbal Space Program forum.