A universe could be simulated, but could they all? I prefer to think that there are symmetry/conservation laws that work bidirectionally in time. Even if time

A universe could be simulated, but could they all? I prefer to think that there are symmetry/conservation laws that work bidirectionally in time. Even if time travel were possible, the only events that could occur are those that don't break any symmetry/conservation laws. This could be seen as a weaker form of simulation hypothesis leaving out the concrete 'how' as an unknown. I remember coming up with the idea of 'time legs'. A tree can't pick up and move somewhere else, and a falling leaf doesn't choose its path. Other creatures can. We just don't have the apparatus to move freely through time--our memories only form when moving forward.