* LimitedSpecialCollectorsUltimateEdition: For those who donated to the Kickstarter:
** A stretch goal was reached that allowed some form of this.
*** Those who pitched in at least $35 got a digital copy of the official guidebook, which features detailed information on the mechanics and the backstory.
*** [[WhatCouldHaveBeen Had the project achieved another goal]], those who put in $45 or more would've received a physical guidebook in addition to the digital one, and yet another goal would have resulted in physical copies of the games and soundtracks as well as a set of postcards.
*** As a consolation prize, those who pitched in at least $45 instead got the "Digital Deluxe Edition", which includes high-resolution images of the box and CD label art for the games and soundtracks. A do-it-yourself collector's edition, if you will.
** Regardless of the stretch goals, higher tiers yielded items like T-shirts, a plushie of SITER SKAIN's mascot, and even a bodypillow of Alice.
* ScrappyMechanic: All of the games require you to complete a given stage to unlock it for practice mode, meaning that to practice [[ThatOneLevel a stage that's giving you trouble]], you'll need to be able to beat it in the first place. This isn't a big problem for ''KAMUI'' since it has infinite continues right off the bat (and thus you can basically unlock all six stages for practice with relatively little effort), but ''[=RefleX=]'' and ''ALLTYNEX Second'' don't have that same luxury.
----