Only thing from the original this sequel sort of misses...

is at least one encounter with an unearthly creature. I'm not counting the Clay People since they were originally normal men and since their minds remained reasonable. I mean there should have been a couple of instances of Flash and company getting spooked by outright monsters. I mean monstrous animals as indigenous to Mars as the creatures (like the giant lizards) in the other two Flash serials were indigenous to Mongo. Although the original did overdo the cheesy monster thing, the lack of alien animals in "Trip to Mars" is a little extreme. We definitely should have seen some in the forest of the Tree Men.