Space Invaders ++
Have a look at the following three screenshots, which visually explain most of what we need to know about Space Invaders ++. Just in case you don't know already, Space Invaders is one of the earliest arcade games and was released in 1978. If you like a bit of history, you can read the Wikipedia Space Invaders game page here: https://en.wikipedia.org/wiki/Space_Invaders.
This first screenshot shows the simple starting screen of our game. For the purposes of discussing screens, which we'll do next, we will call this the select screen. The player has two choices to select from: quit or play. However, by the end of this chapter, you will know how to add and switch between as many screens as you like:
As you can see, in the preceding screenshot, there is a new feature we have not implemented before: clickable buttons. We will talk more about buttons and their counterparts, such as UI panels and screens, shortly.
The following...
