Have Fun.

Tip: When things seem a bit weird, press X to use Eversion.

Also, don't post any spoilers without proper warning, also make them highlight only.

Interesting stuff (Spoilers: highlight to see): On the last few levels, the "Ready!" screen shown when you start the level, or when you die, changes. The new things it says are: "behind you, ready! to die, game over, give up, a black screen, stop, i see you, mother" There is also extra content for collecting all the gems. There is also a new ending, but I recommend leaving a gem or two in order to see both endings.