TwoDPhysics is a 2D rigid body simulation add-on for Blender 2.80. Since Blender 2.8, it is now possible to create a fully fledged 2D animation in Blender using grease pencil or other means. And there isn't a dedicated 2D rigid body physics engine for Blender so far. The existing physics engine is dedicated for 3D simulations and it requires all kinds of circus to create a 2D simulation using it. So here's the answer to that. Currently it is available for both Windows and Linux.