The game is more or less a straight mix between Bomberman
and Gauntlet, using enemies and levels from
Gauntlet, and the main character, attack system and power-ups from Bomberman.
The graphics limitations and sound capabilities are intentionally similar to those an 8-bit game console.
Specifically, the graphics have the same limitations as the
Sega Master System, while the sound is similar to
the sound chip in a Commodore 64.
There's no copyrighted material in the game. While the graphics might appear similar to that of the original games,
everything has been made from scratch (in Paint.net).
To play the game, simply go here. Instructions on how to
play are included in the game from the main menu.
To play the game offline, download this file, then
open index.html in a web browser.
To host your own multiplayer server, download this file, and
follow the instructions in readme.txt.
The screen resolution is 320x240 pixels, mostly because I LOOOVE that resolution, but also because the competition rules state that I have to show a splash screen of at least 640x480 pixels. Since I display the graphics at a X2 zoom, this fits perfectly.
All graphics are limited to the Master System 6-bit palette:
There's a sprite palette of 15 colors (+1 color for transparent) from that master palette which all moving
graphics share.
Stationary graphics use another palette of 11 colors, with the last four colors dedicated for floor and wall
graphics. That way, I can simply change the colors of the four last colors in that palette to dynamically change
the colors of each level.
The only place I really cheat is with the number of visible sprites, and with the speed of the graphics rendering. The opening animation, for example, would probably not be possible on a real 8-Bit computer.
When loading the graphics, I apply some desaturation and gamma correction for a more genuine TV appearance.
If enabled in the options, I also do some minor image post processing that adds some slight vertical blur.
SOUND
I didn't have the energy to implement a full SID emulation, so I made my own virtual sound chip called the SYD.
It has the following specifications:
3 Analogue Stereo Waveform Generators
1 11KHZ 4-bit PCM player
Programmable interrupt
Ring modulation between any two waveform generators
The programmable interrupt used for triggering notes in music in a timely fashion.
Inputs for the waveform generators:
bits | name | description
-----+-------------+-------------------------------------------------------------
16 | hz | Starting HZ for the note
16 | hztarget | Ending HZ for the note. Used for slides
4 | saw | Saw waveform volume
4 | triangle | Triangle waveform volume
4 | pulse | Pulse waveform volume
4 | noise | Noise volume
4 | duty | The duty cycle of the pulse waveform
16 | ADSR | Four bits for each element. ADR is in logarithmic scale.
2 | channel | Stereo channel mode. 0=center. 1=left. 2=right. 3=sign split
2 | filter | Filter type. 0=no filter. 1=lowpass. 2=highpass. 3=bandpass
4 | f.strength | Strength of the filter
I believe this should be a fairly accurate interpretation of the sound capabilities of 8 bit game consoles.
GENERAL
The game runs at 60 hz regardless of computer power. If it's not possible to run the game fast enough, it does automatic frameskipping, but the logic still happens at 60 hz.
Collision detection, rendering, and monster updates all use the same fast space partitioning engine I made for this game. Basically, it just splits the level up into 64x64 pixel chunks and keeps a list of all sprites in each chunk, and provides some fast functions for getting all entities within a certain pixel area.
I totally ignore any cpu power or memory limitations of 8 bit computers, but I have tried to make the game run smoothly even on older computers. After disabling the fancy post processing in the options, the game runs at the full 60 fps even on the very old worst case test computer at work, so I'm very happy with the performance.
--
I hope you've enjoyed this game as much as I've enjoyed making it.
Markus Persson