This update isn't for everyone... It introduces the start of a new layer of the game, where existing levels have had the difficulty ramped up to 11. Have fun revisiting familiar levels that now contain new and extreme challenges.
I'm eventually planning on unlocking "Hard Mode" as a kind of "New Game+" feature, after you finish the game under its standard difficulty. But for now, in order to make it easier to get feedback from players, you'll find a new tab in the "Challenge Modes" screen. Give them a try, and don't be shy with the feedback.
For now, 9 levels have been upgraded with "Hard Mode", just the levels of the Basic Assessment course. The rest of the levels will follow, most likely pairing up with adding the remaining cutscenes/story to the levels.