Fnvader (Channel F)

Background

This is a simple arcade shooter for two players, either against a human player on the second controller, or the CPU.  It was originally written for the C64 by Darren Foulds as an exercise in learning 6502 assembly language, and I always thought it was a neat idea for a casual arcade game.

A solitary invader (who seemingly got lost on his way to a Space Invaders cabinet) descends down the screen at increasing speed. Every time he is hit, he re-spawns two rows higher. Once he reaches the same row as the player ships, the game is over and the winner is declared.

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To start a game versus a second human player, press fire on the SECOND controller to begin. Otherwise press fire on the first controller to play against the CPU.

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How To Play

There is only one control - FIRE! 

When you fire, you also change direction. You can only shoot one bullet at a time so it's crucial to not waste shots that leave you out of position and/or waiting for a reload.

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Scoring

I made one change to Darren's design. In the C64 version you get more points the closer to the top the invader is. I decided to reverse that to make the later stages of the game more tense and add some room for strategy. Victory can be snatched from the jaws of defeat with a couple of well-timed shots on the lowest few rows. 

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Running ROM in an emulator

The .rom file can be played in MAME or MESS, or the LibRetro core FreeChaF.  

You will need to locate the sl31253.rom and sl31254.rom BIOS files in order to successfully play Channel F games. I can't distribute these with the game but they are easily found on Google. 

This online emulator can also be used, as above you'll need to provide the BIOS roms. Drag and drop the ROM image onto the emulator window, and then the bios images as prompted.  https://www.lexaloffle.com/bbs/?tid=34262

From the command line:

messd channelf -cart C:\fnvader.rom -w -r 720x720 -nodebug