Picotron is a fantasy workstation from the creator of the Pico-8 fantasy console (previously at Boing Boing)—an intentionally simple, retro-styled game development environment with a stylishly limited palette, resolution and performance. It's ideal for making "pixelart games, animations, music, demos and other curiosities."
It has a toy operating system designed to be a cosy creative space, but runs on top of Windows, MacOS or Linux. Picotron apps can be made with built-in tools, and shared with other users in a special 256k png cartridge format.
Display:480×270 / 240×135 64 definable colours
Graphics: Blend tables, tline3d, stencil clipping
Audio: 64-node synth and 8-channel tracker
Code:Lua 5.4 w/ PICO-8 compat features
CPU:8M Lua VM insts / second
Cart:.p64.png (256k) / .p64 (unlimited)
64 definable colors! It's like upgrading to an Amiga 500 all over again.