Lets Make a Retro Game – Episode 9 – Enemy Movement

This is the 9th video in my series, where I am going to work through the steps required to make a home brew game for a retro 8-bit console or computer system.

In each episode I will work through various topics, such as tools, methods and design.

All of the information referenced in each episode will have an associated article on my web site.

In the Intellivision game of Astro Smash, that we are basing our game on, the main enemies are Asteroids that fall down the screen, exploding when they hit the ground.

Points are awarded to the player, when one is destroyed and points are removed if one reaches the planet surface.

In this episode we are going to introduce some simple enemy movement, this will involve:

– Using a random number generator to determine when an asteroid should appear and at what speed.
– Moving any visible asteroids towards the bottom of the screen.

I have included the complete code for this section, so you can follow through the various steps without having to worry about typing in code.

The supplied code has two folders:
Start – where we start in this episode and
End – the final code and a copy of the ROM file.

The corresponding article with all download links and more detail on what is covered in this episode is available on my website here:
http://www.electricadventures.net/ViewArticle.aspx?Id=138

Next episode we will be going back to looking at our game and get some objects moving on the screen in response to input from the controls.

See general updates on both my web site:
http://www.electricadventures.net
and my Facebook page:
http://www.facebook.com/ElectricAdventures

I am part of the ‘Press Play On Tape’ podcast, join the mayhem here:
https://www.facebook.com/pressplayontap

I also do live game plays, usually high score practices on Twitch here:
http://www.twitch.tv/electricadventures