This is unexpectedly fun and quite challenging. I don't know if similar games already exist but I could definitely see this expanding into a full game. I hope you're thinking about expanding it.Maybe with some rare cards that can open up wrinkles in the gameplay.
I don't really have any problem with the physics implementation. The feeling of it is pretty good for me. I see our job as being less about trying to model the physics of the real world but improving on them (by simplifying them and/or making them more fun).