When Adam and Eden try to escape from the police for the second time, near the end of the movie, Adam is holding Eden on his shoulders jumping through the big blocks of stone. When a man fires and hits the wire that holds the stone where they're standing, they fall down and Eden grabs the chain with one hand, and Alan with the other one. Then she is forced to let Adam fall down, but doing it, the gravity of her planet should attract her and cause her to fall in the opposite direction of Adam. You can obviously notice that this doesn't happen: Adam falls and Eden is still holding herself to the chain to avoid falling down in the same direction of Adam.
When Adam steps into the x-ray scanner on his first visit into the TransWorld building. The x-ray is that of a woman as evidenced by the structure of the pelvis and other observable differences in bone structure and soft tissue that should have caused shape and density changes if the x-ray was that of a male.
When Adam is Up-side his hair should be falling upward toward Down Under, like that of anyone being held upside down.
(before he goes up-side he sprays his hair with hairspray to keep it from falling up.)
When Adam puts on the weights, it is shown to be placed on his body and legs. However there are none on his arms, meaning he would have to struggle to keep them down and get tired very quickly, but he doesn't.
The TransWorld building is connecting both worlds, therefore matter from one world must come into contact with inverse matter - and according to the laws of double gravity, get hot and burn within a few hours.