I just discovered this gem of a game engine and immediately fell in love with it. The workflow is very fluent and easy to grasp. Kudos to you. :)
Found a few issues :
1) Space Shooter Tutorial:
The degrees for left and right are swapped in the Space Shooter tutorial (see the "Tip" section with the coordinate system circle). It should be 0° for right and 180° for left. https://docs.ctjs.rocks/tut-making-shooter.html#moving-hostiles-and-asteroids
2) Room editor Tileset:
If you create a room and click on "Find a tileset", you get stuck in the search window with no way back to the room editor if you haven't yet created any tilesets. A back button is missing. (ct-linux64-next.zip (alpha channel))
3) ct.js license:
By the way, have you thought about releasing ct.js under an Open Source license? I see that you want to give the users the freedom to release their games under any license they want and also protect the work you put into the game engine and IDE against third parties who would use it to make money. But there are Open Source licenses out there which prevent just that while giving the users the freedom to release their games under any license they choose. Furthermore other developers could help you with the development of the game engine and IDE. What do you think?