Actually its a matter of benefit vs. costs, and in the case of "walking on planets or flying over planets surface" I would say the costs (of development) are tremendous and the benefit (over time) tends to zero. Yes the benefit is a matter of taste, but over time, it will tend to some individual zero line. There are ideas here in this board which are the other way round, high benefit with low costs. These should be adressed first. I can not tell any, because there will always be argues about how easy it is to code this and that, thats not our business, FD can decide this better than we.
Therefor I do not support the idea of planet surface whatever.
+1 for the OP
Rex Kraemer
may i ask what are these ideas with high reward and low risk?