About storing map data, I agree that the initial data should probably bee in the app, then yuo can copy it out when a new game is started. Also, you shouldn't copy the whole map. You just need to copy the parts that can change, whether changed or not. Then, when you run through the map to load it, and encounter a tile that CAN change, you check for the changed value in the level data. It would save at least a couple of bytes.

Is this still progressing by the way? This seemed promising. Also if you go for apps, you have to swap between pages so if you got code or data accross multiple ones in some cases it can get confusing, if I remember.

Also were there ever any screenshots available?