I use Alt-F4 for so many things that I may have forgotten an exit button... I will re-upload a newer version with an exit button.
Thanks for the heads-up :)
The game has been modified to include an Exit button.
To access menu, press "Escape" key and click on the "Exit" button to leave the game. You can also view the current shortcuts for the game.
I am currently reworking the menu to include other settings like modifying the color of active cells, adding presets to the game, modifying post-processing values (bloom, vignette, chromatic aberration, etc...) and others simple additions.
I am also working on a way to improve performances to allow me to include a WebGL version, without being limited with 5-6 FPS on browser (which is currently the case). This is probably an addition to the long run as I need to rework the whole grid creation process.
The Git will also be updated as I keep working on it.