Sorry for taking so long to write, I'm very busy at work.
My games have more than 500 sprites, use tinypng to compress (decreases the download size, but not memory used).
In this picture you can see the memory problem on C3.
To load a small black sprite on all levels, you must load a lot of sprites that you would not have to use.
And worst of all is that against more sprites has the game, the more memory you need to upload images that you do not use.