Retro Menu

Classic PC
CGA 320×200 4 color fixed palettes (4 options)
EGA 320x200 16 color fixed palette
VGA - MCGA/Mode 13h 320x200 16 or 256 colors from 18-bit RGB default palette provided For the jam: up to a 64 color palette
VGA - QVGA/Mode X 320x240 256 colors from 18-bit RGB default palette provided For the jam: up to a 64 color palette
Amiga 320x200 32 colors from from 12-bit RGB
C64 16-color fixed palette 320x200 2 colors per 8x8px block 160x200 4 colors per 4x8px block (details)
Apple II hi-res 280×192 6 color fixed palette
Consoles
Game Boy 160x144 4-color monochrome / example palette
Pico8 128x128 16 color fixed palette
NES 256x224 3 colors per element effectively 25 colors at a time chosen from 54 or 54
Other options:
Flexible <= 100K pixels Any palette <= 64 colors	For options not in the above list, or a slightly relaxed version of the above (e.g. NES but with all 54 colors available), choose any resolution smaller than 100,000 total pixels, choose a palette with no more than 64 colors.

References: