I have found 2 glitches on release day. Both here:

Glitches start at 2:20

For the Intro Skip/Course 5 early you slowly walk over the stairs before the rocket and fall through. Then just walk through the door like in the video.

For the Out of Bounds in Course one, head to the right to the wooden platform, when walking against a crack in the wall, you can clip through and clip up to star one or clip in the cave in which Mips is hiding.