I gave up.
Apparently, I couldn't achieve what I did last time. This contest is a major disappointment for me.
There is probably a lot of reason why I couldn't finish it. Lack of sleep, lack of willpower, too ambitious, etc.
Whatever the case, qubodup and I are too crazy. Maybe someday, I'll be able to code a whole RTS game within 48 hours.
At this point, I am just an angry programmer. I don't want to code more.