This is going to sound silly, but in my current project I'm using the image manipulator to place tiles, objects etc.
For instance, to place my ground tiles I simply draw a black pixel in an image of say 32x32.
I can then have the image manipulator test for that color, and say if the color at loop x 10, loop y 32 is black create the object ground tile at x of 10*10, and y of 32*10.... In a layout that is 320 x 320. 3200 would be *100 etc.
Now that might sound limiting, but when you think about it you have 255 states for red, blue, and green, meaning you have as many options for items as you do for colors... literally millions when you take alpha into account.
With that in mind not only can you create sprites by color, you can also give those sprites attributes like angle, size, and even private variables.
All you have to do is create your own special palette, and figure what you want them to represent.
No special level editor required, just any old image editor.