AI: THE SOMNIUM FILES - nirvanA Initiative (JP)

3rd class cabin will appear after earning
it will then show up in the bonus menu and cost 999 eyeballs to unlock
if you're familiar with Kotaro Uchikoshi's past games this should be extremely familiar to you. it's a carbon copy of the first puzzle room in Nine Hours, Nine Persons, Nine Doors (aka 999). even if you're not familiar, it's pretty simple to solve, and if you do get stuck you can use a guide from 999 since the solutions are identical, actually even simpler because it automatically combines and uses items for you. so in the end all you really need to figure out is the right number combinations.
here's the guide from the original game if you do get stuck https://www.thonky.com/nine-hours-nine-persons-nine-doors/th...