There is no sound ? :'(
The fact there is no guide makes it impossible to win on the first try : you're only able to win once you know where the different tasks take places. The mix between mouse and keyboard control is a terrible idea : if you should have your two hands on the keyboard, make it possible to advance in the dialogue by pressing a keyboard key (especially if the timer starts right after the last line of dialogue).
The concept is fun and i like the implication that billy's candy is in fact drugs that modify his perception of time.