It's insanely fun.
Every round you get an empty ship template.
All the ship piece tiles are in the middle of the players, upside down and mixed up. Someone says "GO" and you start taking pieces one at a time and build your ship. Each side of a ship piece has either a single, a double, or a universal connection, so where pieces touch it's either (single to single or universal), (double to double or universal) or (universal to universal).
Note the connections clockwise from the cannon, double-double, single-single, double-universal, universal-universal.
There are a bunch of other building rules, like cannons and engines can only aim into an empty space. Once you place a tile you cannot change your mind, it's locked in. If you picked up a piece you don't want, you put it down face up and someone else can take it.
So you're all building your ships as quickly and carefully as possible, and when you finish you grab the tile that represents when you finished (1, 2, 3 etc). That's your starting position for the round. The first player will encounter pirates first but also get to explore planets and grab the best cargo. Don't be first if you don't have a lot of cannons, you'll get blowed up. Your position can change depending on how many engines you have (how fast you are).
When everyone's done building, you check each other's ships for illegal connections. Any illegal connection results in pieces being removed until the ship is legal, and destroyed parts cost you points (space $$$).
Then you go!
You shuffle the adventure cards, each turn in the round you draw one card.
You try and survive the meteor showers, pirate attacks, space commandos and other bad things and pick up as much sweet, sweet cargo as you can. If you survive to the end you count up your points and that's the round. Early rounds you get a small ship, some games you use insane ships. It's mad fun.