This version of OE is more developed than the steam next fest demo release you might be familiar with. Below is a list of significant changes. There are definitely more (many of which are bug fixes and other refinements), but these are the more observable ones:

• A largely finished bossfight for World 1.
• Early versions of World 2's sub levels (there are 3: Cowboy, Greek and Noir).
• Reworks for much of World 1's content, such as a dedicated questline for repairing the gondola, a rework for Zuppo's soup quest to make it tremendously less annoying and misleading, a simplification of Professor Purple's laser puzzle, easier routes for Wickedly Cruel's trials and more.
• A new system in the pause menu to keep track of which coins and portal worlds you've visited.
• A whole time trial section in World 1, sub 3's lava section.
• A fully mocapped and voiced cutscene with Wickedly Cruel.