Well , this is a project that pushes an 8-bit ATMega32 microcontroller to the limits.
As you guessed from the title , it is a game system. Here are some of the specifications :
*27MHz overclocked (from 16MHz) AVR ATmega32 microcontroller , with 32KB flash , 2KB RAM.I think you can also use an ATMega644.They have the same pinouts.I personally haven't tried with an atmega644.
*128x64 monochrome KS0108 based display
*4 Voice sound engine : (Sounds the same as the NES)
*2 Variable volume square wave channels.
*1 DDS (Direct Digital Synthesis) Wave table channel with fixed volume , that can play : Sine waves , Triangle waves , Sawtooth waves , Square waves , or any other simple waveform.
*1 DDS White noise channel (Basically the same as the first wave table channel , but this one uses a white noise wave table).
*Frame buffer based video driver : (Penguin uses a video driver that is very advanced compared to the other graphic libraries you find on microcontrollers with KS0108 LCDs )
*Instant color inversion effect
*Sprite drawing with fixed height of 8 and X Scaling (fast)
*Sprite drawing with fixed height of 8 with both X and Y scaling (slow)
*Vector graphics with rotation
*Geometric shapes drawing : Triangle , Rectangle , Circle (no fill for any shapes)
*Multiple background drawing (for transparent backgrounds)
*Draw_pixel(x,y) function (pretty self-explanatory...)
The video driver uses 1KB of RAM for the frame buffer , and has around 30 FPS with a transparent background , sound engine running and 50 sprites on the screen.
There is no background limit,sprite limit or anything like this.The only bad thing is that if you draw too much stuff on the screen,it gets slower and slower.The vector graphics functions use a proprietary format that is generated by a tool you will found in the "Tools" category in this instructable.