After playing a game of Tetris in the Linux console, it came to my attention how dynamic the console can be. I began to write a Bash version of a typical (shoot-em up) space invaders game. I was inspired by Phoenix for the TI-83 graphing calculator, an old treasure.
While building this game in Bash I encountered the issue of a delayed screen refresh. Every time something is written to the screen, an OS call must be made wich takes time. To overcome this issue, rather than updating the entire screen each time something changes, the old region is overwritten with blanks and a new region is drawn in.
The game is a great success but does suffer from some lag issues. This adds some additional challenge to the game play. I constructed four levels and a state machine. Reminiscent of Phoenix, I added a health upgrade that can be purchased with the collected falling money.