Yes, i have a good feeling about the game if it would look nicer... and it would provide a nice "Story", some kind of progression, something where you need to make decisions or figure something out. What is currently there is nice for a gamejam and for toying around, but it would need much more effort to get it to the next level. The reason i made this game was that I had the Obi Rope asset sitting in my library and always wanted to do something with it :-)
I dont think the Subtractive color space, or even introducing the "Art" color space (RBY) would really bring it there. I have some ideas about obstacles (little fire pits that sever the rope) or multistage levels where you unlock something that lets you access another part. But all of that will then require a good ability to create interesting puzzles, and I think I am not that great at it :-) ...
I will want to polish the game a little more, introduce a timer and also finish my idea of a level editor with the ability to share a level text string to others and competing for best time. (the levels can have a JSON and a string representation) But outside of that I would need to have access to a 3D and 2D artist and best also a composer and sound artist to make it good.