Requirements

A text editor

Notepad should work fine but I’d recommend notepad++ because It will make things easier.
I used VS Code but that shouldn’t be necessary unless you plan on writing code yourself.

Fullscreen

First you need to go to:

There you should open main.js with your text editor. (Probably best to also make a backup)

In there you should find something like this:

Width and height didn’t seem to change anything for me and since we’re going fullscreen anyway you can probably just leave them.

Now, for the fullscreen experience you can either insert:

This is more of a borderless windowed as you can still drag the window around but this will also leave the taskbar visible.

Or you can insert:

This will simply make it fullscreen.

It should now look something like:

If that’s all you wanted, you can stop reading here but otherwise keep going.

DevTools

Developer tools let you access background data and are present in most browsers. Since this is essentially still a web app, you can still access them although they have been disabled.

So, still in main.js, you’ll first want to change:

into

Now they are enabled but you still can’t open them so a little further down you’ll find:

which you need to enable by removing the ” // ” so:

The ” // ” makes that line a comment so the computer doesn’t read them.
Changing this makes the dev tools start up along with the game.

Achievement

For some reason the second achievement seems to be bugged for a lot of people (including me) so when me and my sister finally completed all of the levels on green I was pretty annoyed the achievement didn’t trigger.
I still don’t know why but I did find a way to trigger it regardless.

So what you need to do is in the dev tools go to the console tab and type:

For the first achievement.
or

For the second achievement.

I know this is technically cheating but since it doesn’t work in the first place, I don’t feel bad about it.
(If anyone with authority wants this gone, I will happily remove this section.)

This is all for Fireboy & Watergirl: Elements Fullscreen & Achievement Fix hope you enjoy the post. If you believe we forget or we should update the post please let us know via comment, we will try our best to fix how fast is possible! Have a great day!