kriper

You need physics in order to make movement server authoritative. Otherwise player will be able to fly around and ignore collusions. You might need animation state in server if you are making a fps shooter and want to calculate raycasts properly.

How would you simulate physics, pathfinding, animation state on the server using this tech? Do you have to ditch your engine (do I have to reimplement what unity/unreal gives me for free?) ?

I don't really understand how you would write a game server using this tech. Lets say you need to simulate physics, pathfinding, animation etc on server. How one would integrate all of this? In regular world you just use unreal/unity headless mode that includes all of this but using spacetimedb requires ditching the game engine and reimplementing everything from scratch?

Does it mean that if I have a physics engine written in c++ and want to use it on the server I have to compile it to web assembly?

in C# it's basically automatic https://github.com/microsoft/coyote/