The closest I've seen to that ideal is Noita - every pixel if its (2d) world has full chemical/physics simulation. Overall its quite reminiscent, and certainly

The closest I've seen to that ideal is Noita - every pixel if its (2d) world has full chemical/physics simulation. Overall its quite reminiscent, and certainly inspired by the 'falling sand' flash game from the 90's. Of course it doesn't quite qualify as a realistic simulation but still quite impressive.