"Let's release this major update RIGHT when school starts!"
He said, cackling evilly.

3 new enemies!
*I guess you could say they're tough as nails.

1 new boss!
*It's pretty well rounded. In multiple dimensions.

Added some totally unsuspicious pedestals with free items on them
*What are you waiting for? Just grab the item! It's not held down or anything. Yeah, that pedestal does have something written on it but it's all smudged over with dirt and in any case probably just says "free item!"

Unrelated, added one new miniboss! It's the only thing in the game other than the quit game button that can one shot you.

Added blue and red emeralds!
*Sort of. These were in version 1.5.1, but weren't used in any level layouts and thus left unused.
*Blue ones are worth 5, and red ones are worth 25. You know, powers of 5. 5 green = 1 blue, 5 blue = 1 red. No, the red ones are not worth 20, that would be inconsistent. And too blatant of a ripoff.

New item!
*The velocity jar! For if you want to put your speed in a jar and do an overly simplified reenactment of a Super Mario 64 glitch.

There's also another new item, but it's only available during the new boss fight.

3 new cards!

Added new mechanisms!
*You pull the lever, it opens a door. You push the lever, it...closes the door. Uhh... not sure where I was going with that.
*Oh, yeah, there's motion sensors now. They also open doors. Sometimes, you might not want those doors to open. If you accidentally open a door that you did not want to open, please run to your nearest bedroom, crawl under the covers, and quietly weep.

Many existing level layouts have been redesigned. The general pattern is, "There is a puzzle here, but you can cheese it or skip it entirely with the right items"

The same section layout can no longer appear twice on the same floor.