Hello Luni,
Wanted to add to the conversation to say I disagree that those who create their own art export frame-by-frame by default. Honestly, I would say the contrary which is why most major and small engines that support 2D (Unity, Godot, Construct, etc.) allow the importing of Sprite sheets. I’m not an expert artist by any means, but I try to create my own pixel art for important resources. I use Aseprite and prefer Sprite sheets by a wide margin as it just helps keep my projects cleaner and more organized. Here’s an example of a walk cycle with 16 frames.
The organizational benefits are immediately obvious - especially for detailed animations with many frames. Having all of these files really clog up the resource manager in GDevelop as well which is a major pain as there is no project manager with folders.
If you have dozens of multi frame animations it makes the resource manager frustrating to navigate as you’re scrolling at best dozens if not hundreds of files that are all part of the same resource. Having all of those files bundled into a single character sprite sheet with all animations would be SO much cleaner.
Last note is on performance. Advantages here seem immediately intuitive. Just as a quick example take a look at the screenshot below. The file size containing all frames of the walk cycle is 23kb while the sprite sheet itself is only 5kb. The exports are all from Aseprite from the same file with the same resolution and file format. Only difference is how it is exported in a single sheet. While file size doesn’t necessarily equate to performance the reduction of nearly 500% for each animation cycle (23kb → 5kb) will undoubtably help with loading times when scaled to a large release game. I would say super important for GDevelop considering that all resources front load when a game is started from my understanding. Not an expert here either, but those are my observations.
Hope that helps with some additional user perspective!
All the best,