Suggestions

[friends] — You urgently need to change the way you add friends. When a user takes too long to accept a friend request, we should have the option to withdraw the request or reset it to be able to add other people. Or at least, it should already work according to the link on Facebook, let's be honest, it's a pain having to use code, copy and paste, especially for those on mobile.

[for the wait] — There could be other activities so we don't have to leave the game open like a banana while waiting for materials to be manufactured. Maybe those matching games themed to the game could be added, in a dynamic like "for every 10 matches, you earn 1 dollar."... 

[adds] — Also, we could have characters to use as profile icons, it could be something to be unlocked through out levels, it could also be linked to the previous mini-game idea. Female and male characters please...

[passtime] - May some story could be added, something related to the theme of course, maybe in chapters that unlock through other things and stuff like that.