And it is done.
Not quite, I should say. After painting this for more than 10 hours, Corel Painter had been slowing down. It was also slow when I tried to push Command+z, which took more than 1 minute to undo each part of the work. Later, Corel Painter literally crashed 4 times, causing my work to be unsaved, which I had to redo everything over again.
I shouldn't that this work was easy for me: it's far more difficult due to art block and the colors, especially the lighting and so forth.
Nonetheless, this work was meant to have an urban-feel. It was inspired by the Japanese graffiti over at the Udagawa District in Japan. A similar work of graffiti can also be found in the game, The World Ends with You.