I managed to eventually solve both "ends" (after many tries and enjoying the puzzle), but it seems I'm now stuck. At one end, through the doors with the forest/greenery, there's a closed door of some sort and a green light, while at "desert" end there's a similar sort of door with a red light. It doesn't feel like the game is quite intended to end here, but at the same time, I can't find anything to interact with to try and continue. Any hints?
This is the end, because its demo version only. All puzzles will be in the full version on steam.