Only looks for objects that are neither moving nor doing an action.
[stationary Crate] [?] -> [stationary Crate] [Checkmark] [moving Crate] [?] -> [moving Crate] [Cross]
The player is only stationary when realtime_interval is turned on, or when made that way with the right side of a rule.
Makes something stop moving or stop doing an action.
[left Player] -> [stationary Player]
If referenced on the left side but not the right, nothing changes.