Bonjour de l’Espagne. Congratulations for the project and thanks for making it open
source. I’m very excited by it, and I really want to create my first game with it.
Since i was a child I wanted to make one, I remember transcoding little programs
from Zx Spectrum magazines long time ago, but I lacked the patience to learn
programming. I have used Scirra Construct Classic for creating my first game but I
stopped two years ago when I got frustrated because I could not make my game to
appear in full screen; I searched every post in their forum but nobody has an easy
solution that didn’t make the display driver to crash or mess up with the monitor
resolution. So my question is that if it’s possible to do this with GDevelop (either using the regular mode or the Html5 mode). Also
I’d like to know if I can make my game to look like a CRT monitor, applying a post processing
filter like in Mame or Snes emulators, you know, with scanlines, some bloom and color
saturation, phosphor bleed, etc, something like this snapshot I made:
Fullscreen in GD is very straightforward, just use the action “De/activate fullscreen”, for example add this action at the beginning of the scene.
In native games, it just set fullscreen on/off, in HTML5 it covers the canvas and you can set it stretched (fill all the space it can occupy) or non-strechted (fill all space it can occupy, keeping the aspect ratio) 
About the filters, GD doesn’t suport filters/shaders, you should use sprites with this effect already “included” 
Thanks for the fast response and the help. I never thought about that solution, I could draw the artwork and the sprites that way; maybe someday shaders will be available so I’ll make my game the normal way at the moment. I want to make a classic style side scroller, like Ghouls and Ghosts, Golden Axe or Strider, with maybe some Knytt climbing mechanics. I’ll try the fullscreen method as soon as I can. Again, thank you.
It won’t work if any of your sprites moves vertically. Because then, the scanlines of the sprite won’t be aligned with the others’ effect.
Forget the scanlines (the post-2000 generation hates it anyway).
Do it in pixelart (in SD resolution) ou in HD vectors (in HD resolution).
Scanlines… could not be an extra Sprite object?, of course made by semi-transparent lines and always “on-top” 
Or a lot of lines drawed by a Drawer object?
It could work that way…
But depending on the screen resolution, the “scanlines” sprite will be deformed, making the lines more apparent.
Drawing as many horizontal lines as necessary, with the drawing object + multiplier effect…
Could work. Expensive in processor time though.
In one of my projects, I’ve done “scanlines” using tiled sprite object. Works really well.
thanks i had been searching for this