Lua is a lightweight scripting language that is used by a number of applications and games, and is the language used with Corona. It definitely has its quirks, but it's easy to pick up and easy to work with, and is much nicer than say, Objective-C (the language used for iPhone development).
To read more about Lua, and to download the interpreter, head to www.lua.org.
In the example game, the objective is to fire a cannonball at a target. When the target is hit, it falls down and a new target appears in a new location.
The game is simple, but demonstrates the following