Blocks are falling, music is pounding, can your hands keep up?

Rise of Music Games
Musical games gained immense popularity of the late when Guitar Hero, Rock Band, etc took the gaming world by storm. These games test the players reflexes by listening to some pop music, and watching little bricks or game objects fall. When these objects fall, the player is supposed to hit the right buttons, and get points according to how perfect his timing is.

We've seen some similar game mechanics back then when Dance Dance Revolution was pretty popular in arcade centres (and made its way to the homes of some people). That involved hitting the correct directional buttons.

In this tutorial, we'll try to recrate a simplified game with this form of game mechanics. I'll leave out the music and addition of sound effects to another tutorial. We'll focus solely on the coding of the game for now.

Game Scenario
Do we really need a game scenario for this kind of game? Ok, how about ... musical bricks are dropping down, and the player needs to hit the right keys according to the kind of musical brick, at the right time.

Game Details
The player hits the keys Q, W, O and P for the Blue, Red, Green, and Yellow bricks respectively.
Each perfect timing gets the player 50 points, a good timing 10 points, and a bad timing a penalty of -20 points.

How To Play
Objective: Hit the bricks with the correct key when it falls into the brick outline.

Controls: Press Q for the Blue brick, W for Red, O for Green and P for Yellow.