Added progression system. Now you have to collect the 5 unique items from level 1, then the level 1 trophy before you gain access to level 2. This will be the same system for accessing level 3 (which isn't out yet, but will be soon)
Additionally, the difficulty menu now has some (hopefully) helpful explanatory text and changed it from being a default drop down to a custom-made multiple choice menu.
Check your progress in the trophy room (accessed via the statistics menu).