Hi there @AnTennA!
For your specific requirements (accurate value, frequent updates, frequent querying) the best thing I can think of is to have a dedicated world-state entity with separate components for each type of value (player-count, …) that you want to keep track of. Whenever an arbitrary worker performs an action that modifies one of the world-values it should fire off a command to the relevant world-state component telling about this update.
Because commands are updated by the same worker (i.e the one authoritative over the world-state component) they are processed sequentially and, as a result, you should not have much issues of atomically updating the variables, aside from verifying that your command got processed correctly and retry if not.
The point of having a separate component for each global value instead of putting all values into a single
WorldState component is so that when you start scaling you will be able to split up the handling of updates over different workers instead of a single one that would get swamped by update-commands. If you start hitting performance issues even with this approach then you have scaled up quite a lot and it will be worth investigating multiple global-state entities combined with consensus algorithms or other alternatives.