Screenshots
Watch trailer on Steam ↗黒くないカギで開かないドアはない
Studio ZeF · Published by Marvelous Inc. · Official site ↗
Last updated 6 Oct 2026
A world constructed with sentences. 2D action puzzle game where you get keys, open doors and clear stages by rewriting sentences and altering rules by adding and subtracting the word ‘Nai(no/non/not)’.
Indie, Casual · More free games
In 黒くないカギで開かないドアはない, explore a unique 2D puzzle adventure where you unlock doors and progress stages by cleverly altering sentences. Crafted by Studio ZeF, this casual indie game challenges your ability to think logically and creatively.
About this game
No, Non, Not!
'No door can Not be opened with a Non-black key' is a rule-modifying 2D action puzzle game in which the protagonist, who has the power to manipulate the word ‘Nai(no/non/not)’, adventures through a world created by rule sentences.
Summoned by a goddess, the protagonist is given the ability to manipulate negation and must solve a number of stages in order to rescue the princess.
The protagonist can use the given ability to retrieve the negative word ‘Nai’ from a rule statement and then add it to other rule statements.
Contents (Demo version)
8 stages + α
3 endings in total
System Requirements
Will my PC run this? →Minimum
- OS: Windows10+
- Memory: 1 GB RAM
- Storage: 200 MB available space
Recommended
- OS: Windows10+
