The real joy of bridge-building games is in the destruction. The challenge of making death trap bridges that will crumble at the slightest provocation. I can't be the only person who puts effort into weakening bonds and lengthening rods, then laughing and clapping as a train nosedives into a ravine, can I? There's room for many, many more structural puzzle games in my life, so I was pleased to find Sinking Ship Simulator, a game that understands the desire to watch the world crumble. Here it's about the fun of watching 5000 springs wobbling, tensing, straaaaaining, before the inevitable point of no return, where it all goes a bit Poseidon Adventure.
There's not much of a game in it, yet. Just a demo where you can plop a ship into the water and watch as the stress takes its toll. Well-made boats won't start dropping until you begin plucking away at them: left mouse will crumble any of the structure beneath your pointer, enabling you to lightly distress the hull and watch the pressure spread out. The longer you hold it, the more stress you put on it, and you can even slice right through the whole ship. If that's too benevolent, you also have control of wave height, strength, and frequency.
You can build boats by drawing them out in MS Paint and importing them into the game as a PNG, so that's a little clumsy. I made the SS Buck, and it crumbled before it hit the water.
The sandbox edition is free to download via the Steam Greenlight page. It's the testbed for a more complete edition that the will include challenges like building boats that can travel certain distances, or seeing if your build can survive a hurricane. Though that will only be made if the IndieGoGo money is met.