Every aster eggs Pay Tribute to Something such as Tron movie, nyan cat, Jelly Bean and Flappy Bird. They also has theme to match the Androids Version Name. For Example Jelly Bean Easter egg Features a Game with Jelly beans.
To find the Easter egg for your Android version. Open the Settings Page, Scroll Down to the Bottom and Tap About Phone.
Find Android Version on the about phone Screen then Tap Repeatedly until the Easter Eggs Appear. If you are using Gingerbread instead of Android Version look for Firmware version in the About Phone Page. This method works with Android Tablets also so in Tablets you have about tablet instead of about phone.
Android 5.0 Lollipop
Lollipop Easter egg will appear as a Lollipop image just tap on the Lollipop to activate the Feature. Android Lollipop Easter Egg is a Flappy bird Clone. They replaced the Bird with Android Robot and used lollipops for the pipes. And this version is just as hard as the Original Flappy bird game.
Android 4.4 Kitkat
Kitkat Easter egg will appear as a Chocolate bar. Tap and Hold it a fun sliding game will start. the game features pictures of different Sweets.
Android 4.3 Jelly Bean
Jelly Been Easter egg will appear as a large red jelly bean, tap the red jelly bean and a face will appear. Then a mini game will start the game allow you to endlessly flick jelly bean off the Screen. This game will never end until your battery phone dies.
Android 4.0 Ice Cream Sandwich
Android 4.0 Easter egg will appear as a Pixel art Android robot wearing an ice cream sandwich. Tap and hold until swarm of android robots flying across the Screen. This Animation is a tribute to the nyan cat internet meme.
Android 3.0 Honeycomb
Honeycomb Easter egg will appear as a honeybee with electric blue colors.it is inspired by its name, the color of the honeybee looks same as the OS interface. Honeycomb is inspired by tron Legacy that’s why the Easter egg honeybee creates a word bubble with the word REZZZZZZ. In tron Rezzing means Creating Something.
Android 2.3 Gingerbread
Gingerbird Easter Egg is a Painting. The Zombie themed painting Portrays a Gingerbread man and android Robot in the Middle and around them group Zombies stand around with Android Phones in their hands.