Sorry to raise this thread from the depths but, just in case the author's still around somewhere, there's a slight issue early on.
It's about the time-machine, and dropping through it from the wrong time period. That is, opening it with the button and dropping down.
Basically, just before you loop back to the starting point you can "get out" by holding left or right. I wondered if it was intentional to begin with but, when I went back with climb, found it just led to a variety of voids and wallswims.
It's not a big deal, certainly not a game-breaker, but a little weird.