Since my first day here in C2, mobile games were my main focus. I had many failed games because I didn't know the limits of the mobile device, and other C2's good practices. I would like to share you my list of do's.
*Always make black boxes for every hero in adding behaviors and collisions. Don't use the sprite of the image of the character for behaviors and collisions.
*Don't use sprites for terrains. As much as possible use Tiled backgrounds for layout background and Tilemap for terrains.
*Make sure your game terrains and background are tile based. Use the tiled program.
*Don't use the C2's frame by frame animation for characters with many animations and combinations.
Like RPG characters, the parts should be separated and connected or removed rather than frames.
I suggest using "SPRITER with scml plugin".
*As much as possible for making solid ground. Don't use tilemap's or sprite's individual collision for solid behavior since it will not only risk performance, it'll also make seams between sprites and tilemaps. (A must avoid limitation of mobile device) Use tiled background with 2x2 size with color and make the the tiled background "50 % opacity" so that you can see it. Use the tiled background for solid behavior or jumpthru behavior.
Hope that gave you some tips.