In fact you should try Gdevelop and do some Demo’s. I also used game maker a little bit quite a few years ago, back then I also supported the project with a payment. These days it’s become big and expensive and it’s difficult to even consider using anymore.
So, I can’t really compare with the newest version of Game Maker, but here’s from what I remember about functionality + the little I know about new version (price, and platform support).
In any case, Game Maker is hugely expensive (this is relative to the person considering it, but at least comparing with e.g. Gdevelop), Gdevelop is free.
Game Maker probably has particles for both web android and native (old version I tried was native only, but had particles which worked pretty great, honestly). And Gdevelop does not have particles in HTML/Android. However, instead of real particles, I made some free effects you can use as animated objects with Gdevelop here.
You can export for Android in Gdevelop also, but it needs a little bit of manual conversion or custom compile on your side. But nothing too difficult, and there are instructions for it all.
Speed wise, Gdevelop is also decent in native platform, but I never had any problems with game maker on quite old PCs. So, potentially Game Maker’s engine might be faster, but also might not, especially since the new engine is likely completely different. In HTML 5 games (webgl and android, although there’s an android native option also), you have to be really careful with Gdevelop. This is possibly true with Game Maker as well. HTML 5 gives some limitations. In any case, for browser/mobile games, you must be careful not to use too many actions that are resource intensive, or use them only when needed. This part is up to you as well, as a developer. I personally didn’t find performance of Gdevelop to be 100% perfect just yet (comparing to e.g. Unity), but it might be entirely adequate, depending on your optimization skills, and it’s the only Open Source among those I compared it with.
As for 2D, yes, you can definitely make 2D games with Gdevelop, and it’s the primary type of game you can make. Making a 3D game is not supported for the Web/Android platform and very limited at this point in native platform.
Unfortunately, I don’t remember much else about Game Maker to make a real comparison.
Conclusion? Gdevelop might be more limited (Game Maker probably has more features), but only one of them is completely free. Depending on your specific project, it may be 100% satisfactory or not, and unfortunately you might have to experiment a little, try/make some demo’s and so forth until you get your impression.