Click the alien ships (the growing dots) before they kill you (by becoming completely white). Child, Normal, and Difficult have 18 waves. Gamer has 16 waves. Survival is one wave with no breaks. Muting sounds can be done after each wave and before starting Survival.
The main menu Easter egg is for ages 0-6.
Child is for ages 7-12.
Normal is for casual gamers.
Difficult is for gamers.
Gamer is for Kong members.
Survival is for everybody, but especially those incredible players who think Gamer is easy.
Edge provides an alternate playing style for high scores and for slower playing (such as touchpads.)