Spent a lot of time trying to figure out why the movements were so jerky/laggy.
It occurred to me, as i sat on the toilet one day, that i wasn't stopping the move loop when an object moved from one tile map to another, the result being that it would pass the tile map edge, finish it's move loop then be yanked back again to the tile map edge producing the jerk.
I also made the camera a bit more floaty. Anyway the result is now a much more smoother experience.
I also started a menu bar to show how many ufos are on the map and, so far, how long they've been flying around.
You can also now click on one of the menu items to chase the corresponding ufo.
Graphics are a place holder.
You try version 2 here. https://dl.dropboxusercontent.com/u/159885981/loan2/index.html