Although the controls show an X-box controller, everything worked fine with my PS3 gamepad. Only one thing, to go back to the menu I had to press Esc on the keyboard. Since <Start> is already used for resetting the level (which seems to be the right button), it should be possible to press <Select> (which seems to be unused).
I only played the test area, but I've seen a video stream of a play-through. I can safely say it'd be too difficult for me, but that's just me being not too good with that exact platforming required...
Is it an easter-egg that you have to press <Down> to have enough jump height to reach the last room of the testing area? (I can't remember having seen that bit from the play-through stream...)