The key/door was placed there on purpose. I want player need plan each step, just as you said, now the buttons should be in odd numbers step and the doors should be in even numbers step.
In my plan the past oneself can push play if player use that function, i think it will make puzzle design more dynamic.Unfortunately, I don't have time to add him.There should have been two more levels originally, It takes 2 to 3 rounds of using the teleportation mechanism to reach the destination.
