I like the concept of this one!  Really awesome idea.  I'm a fan of lineart and I tend to use it a lot in my pixels, too.  One thing that might help with smaller pieces, though, is to cut out unnecessary lines when trying to fit more detail into a smaller work.  Sometimes it's just part of a style and that can be cool. But other times it may detract from a piece when you want viewers to focus on something specific.  It can often times help to keep your picture cleaner without so many jaggies.  Another thing to keep in mind is the palette you're using.  I don't think there's anything wrong with your colors you've chosen, but, even though it's not an extreme case like your "Well" submission, there is still a large amount of colors being used that may be able to be consolidated for such a small canvas.  It's another tip for being more precise with your shapes and pixels you put down while also helping keep your final submission clean. I hope those little criticisms help and Keep up the great work!