How often do you remember a certain classic game and think to yourself those were the days? With all the variety of new games that you can play on your smartphone today, theres something special about finding one that takes you back to the past. If you want a proper nostalgia trip to, say, the 80s or 90s, you might want to try retro emulation. It allows you to play games from nearly any video game system on your Android device or PC.