Raspberry Pi is a wonderful platform to rely on to learn electronics. Adafruit has posted a new guide that shows you how to build your own game console using a Raspberry Pi 2 computer. It has various buttons, a small audio amplifier and speaker, and 2.8″ display.
You are going to need a Raspberry Pi 2, 2000 mAh battery, PowerBoost 1000c, gamepad, metal speaker, PAM8302 2.5W Audio Amp, and a few other parts to complete this project. More information is available on Adafruit.com.