Just an extra information that I found in the past few hours and could be useful to anyone trying to reduce memory usage:
When I downsized normal image sprites (even the big ones) the memory didn't go down much.
But then I downsized a sprite with animation and it went down 100MB!!!
(The sprite was present in many layouts, but it's still amazing! Makes sense, though)
So from that moment on, I just went for those sprites and got my game down to 150 in minutes.
Hope this is helpful!