Sinking Simulator is not a game per se, rather it comes from that genre of aimless 2D simulator physics engine that with only minimal experimentation can provide enormous amounts of fun.
As the name suggests, the program opens up a cutaway view of an open ocean for the player to define the depth, roughness, bouncy, and so forth of, before dropping a realistic and accurately reproduced model of a to-scale sailing vessel into it. Right out of the box, as it were, the game already contains a slew of famous ships – the Titanic, Britanic, QM2, just to name a few – and more than a dozen basic templates which you can further edit and share with the world via the Steam Workshop. This has a lot of potential in its current state, and looks to be still receiving updates at some point in the future to possibly start adding even more features such as tiny NPC sea-goers or dynamic fire.
The physic engine does appear to be well optimised, so much so that even a fairly basic modern laptop is fine for simulating decently sized bodies of water, the whole program is shockingly small in filesize (weighing in at a lean ~85mb), and that even includes a whole roster of blustery Nineteenth Century sailing dirges have the band play on to.