Finally some progress.

After various problems I decided to put the components together using a universal PCB, both for electrical contacts and mecanical suport for them.

Many changes since the original idea (I will update the components list later):

Now I'm using the 5110 LCD display (same as the old Nokia phone), and my idea is to use a CR2032 coin battery, with a step-up module to convert the 3V of the battery to 5V necessary for Arduino.

At least for now, there will be only 2 buttons (Left and Right), for sake of simplicity.

I managed to soldering the Arduino, display and the buttons in the PCB. Besides this I wrote a very crude first draft of a breakout game. This took me aproximatelly 2 hours of work, which seems very good for me. 

Next step is connect the power (Battery and step-up module), sound (a simple buzzer), and fit everything inside a TicTac plastic case.

Some pictures of the progress so far (probably the worst soldering you have ever seen):

Thanks for reading.