I really appreciate having a build you can instantly try in your browser! 😁 Note that I have not watched the tutorial video, so that I can test the software's intuitive-ness.
LEVEL
I started with the level "Trial of the Great Desert" by Kanami. (I checked all the checkboxes including "Story start only".) It was interesting, but somewhat overwhelming. Do all the levels share one story? The plot at the start made me unsure as to which level I should have chosen first. The characters talk a lot about unrelated lore pretty much unprompted, and I very quickly forgot where I was supposed to go (Maybe that's just me though...I'm tired today)...of course, I soon figured out I needed to go north to start the level. To make the initial experience be less overwhelming, consider adding a dedicated tutorial level easily located on the menu. It could introduce the lore and characters, but leave the unrelated details to be revealed when they become important, which would make the conversation feel more natural.
Side notes...
* It's really charming how awkward Autem the dragon is, like catching himself using contractions ("I'm") in order to sound more dragonlike and then abruptly leaving like..."Bye!" 🤣
* I didn't do much of the actual combat gameplay, however.
* It can be tough to make dialogue advance quicker. When I press the spacebar while the character is still speaking, I expect the text animation to finish instantly, like in other games. (I'm a speed reader.) Then, ideally, I can press it again to see the next dialogue. The way it works now still leaves me feeling impatient, since the text only speeds up a little bit as you hold the spacebar. Due to my muscle memory, I found myself repeatedly pressing the spacebar, making it easy to accidentally choose options before I can read them.
EDITOR
...I'm using it now, and to be honest I'm pretty lost!
* I feel like requiring an account login could be a barrier to getting people to test your level editor. Maybe it's just me -- even though it's not a lot of work, I don't like having to keep track of yet ANOTHER account. Fortunately, this game requires just a name and a password, though; no email or any personal info as is the norm for user accounts. However, others may assume you'll want their email or something just to try the editor, and tune out.
* The Important Starter Resources screen was rather confusing. What does that "C" button do? It's also not clear that you must double-click the starter package to continue. Perhaps put checkmarks next to each resource and an "Import" button next to the "Cancel" button. That way you can easily import multiple packages.
* The main interface is overwhelming. I should have read the intro text better (I tend to skim, since I use a lot of game dev software and usually have a vague idea how it works, apart from tutorials) because it explains "Create a new room and edit it in the Rooms tab." Without that knowledge, I thumbed through the other tabs wondering how to get started. There seem to be an impressive amount of features, but my instinct is to start putting tiles and objects down ASAP, and I'm not able to do that.
* Besides the menus themselves, there is little visual indication (large headings, etc.) whether you are in "edit whole world" mode or "edit room" mode. That could be confusing for newcomers not used to editing software, who may wonder how to return to the former. (You have to click the small X.) Further playtesting can check whether this is a problem.
* Just by looking, it's not clear which items will spawn tooltips and which will not.
* Even after figuring out how to create and edit a room -- perhaps the software should create the first room for you, and start you off editing it! -- I have no idea how to put tiles on it. There's just a black canvas where stuff could be.
...And that's where I'm stuck right now 😮 I don't know how to start putting down ground tiles or objects.
Still, this is a cool idea for a game. And it's clear that cool things can be done with the editor, such as story scripting. For the editor, I would look at well-designed interfaces such as Super Mario Maker or the well-loved free tilemap editor "Tiled" for inspiration. (There's also OGMO editor, which I've never used, but it's by Celeste devs and it looks stylin'!)
Read up on User Experience design as well as User Interface design...those are two separate things! Try to make things more visual and easy to understand. Reduce the amount of unnecessary decisions beginners have to make before they can get started. For example, you could pre-load the game with a starter pack of tiles by default, while allowing users to also add or choose custom ones.
Good luck!