I've gotten notice of a rather powerful, flexible and surely open source level editor people like so much today. Its called Tiled. That's just the name of it. Really. No joke.

It's said to be helpful in people designing levels in games to work on, be it a platformer, RPG, or whatever they choose. And I have to say, it is really a neat program to make levels for games with it. Its workflow is said to be powerful, being able to switch between projects quickly, for instance, and its supported by many game development frameworks, both existing, such as Godot, Unity, and Game Maker Studio, and custom-made frameworks.

Many known games have been made with that editor so far, such as Shovel Knight, Axiom Verge, and Alwa's Legacy. I can still imagine other games that could still be made with it.

Making maps for levels is neat in that program, but the thing is for people to make the tilesets & parallax backgrounds in whichever program makes them, be it pixel art or otherwise, and have it convert them into formats, such as .TMX, .TSX, & .JSON. People who use it can also place enemies, bosses, be it mini-bosses, major, or what else, and other obstacles & hazards they place in, and, so on. Loads of amazing uses!

If you're eager to try it, then, go right ahead. The download is entirely free! Really! Not a single penny just to use it! It also has a donation option to pledge support in helping make the level editor better. That's optional, but still neat, too.

Did I mention it has the ability to see levels with parallax preview from the editor itself? It does! It is rather really cool to have in a level editor rather than have to see the changes each time the programmer or designer makes them through trying them by playing them each time! Very neat while working on platformers! Here's a video of it as proof: https://www.youtube.com/watch?v=s6Yb5v96l04

Here's the site for it in case you may be interested in trying: https://www.mapeditor.org/

And the Github page, too: https://github.com/mapeditor/tiled

So, if you're that eager to give it a try, why not now? I'm sure you'll enjoy it once you get the hang of it. There's a manual for it(constantly worked on as the program updates. Contributions can help, too, when needed). Here's the link if you want to read it: https://doc.mapeditor.org/en/stable/