Hi,
there are some platforms on the floor you have to find, they are hidden in the ruins (search for it on top of the columns, stairs.. it will open doors to next levels. There are three levels with variations on everything, sky, colors, music, mood, story.. the game becomes more interesting as you find the small platforms with an "eye" icon on it to open many doors...
About the lag loading on the GO, it's strange.. because I am having very positive reviews and the game is super optimized for mobile VR. No more then 10 seconds of loading the entire level...