In my experience, the development of puzzle game using C2 was not as flexible or friendly for mobile depending on the number of collisions. It affects poor performance.
This suggestion is very important to people think to use puzzle genre with C2, as currently is not advisable until Scirra should have a new official plugin.
C2 and is good for making platforms, action, RTS, physical, adventure, special effects, etc.. but the puzzles are another story.
The idea of ??plugin is not using the collisions so maintains good performance for many instances in mobiles. Also applies Grid movements and other options are necessary.
This is a suggestion, please consider this suggestion would be useful to meet the needs of all users of C2.