I play your game, "skyline", I feel there are many deficiencies.
For example, why do I need to press esc to open the menu?
Moreover, there are bug, the upper left corner "aimed Cross" of the screen.
But it is still as it was like, I do not know how to play.
However, although there are many problems, but he still is a complete game.
However, I would like to ask, Allegro supports transparent bitmaps do?
I checked your picture, found a lot of purple background, can not directly use the transparent background?