D. Scott Williamson is a former Atari employee with a decades-long obsession with the game Star Castle, once a popular stand-up arcade game. In 1981, Howard Scott Warshaw, a well-regarded Atari programmer, gave up on porting Star Castle to the Atari 2600, calling the job impossible (Warshaw ended up making the beloved game Yar's Castle instead).
Decades later, Williamson dug out his old Atari development materials and set to work trying to port Star Castle to the now-defunct 2600 platform, trying to cram the game into 8 kilobytes, and accommodate it to the quirks of the Atari hardware and TV linkup. After a false start or two, he produced a genuinely delightful and playable port.
Having perfected his code, he undertook to produce a fitting physical medium for his game. He made his own scratch-built Atari 2600 game-cartridge, one that could show off the blinkenlights he included on the circuit-board. And to make sure those lights were visible during gameplay, he also produced a transparent perspex Atari 2600 clone. Also, he made a beautiful box to accompany his cartridge, shelf-ready and perfect for displaying at one of the many non-existent Atari 2600 retailers that don't dot the landscape.
Now he wants to mass produce his delightful atemporal anachronism, and he's running a $10,000 Kickstarter to fund the production of cast cartridge shells, custom-programmed circuit boards, CDs (containing versions of the code that can be played on modern hardware), manuals, and boxes: "I was inspired by one of the greatest and most influential game programmers of all time to make something that he said was impossible. I don't consider this a game development project, rather an alternative history art piece*, a demonstration that it could indeed be done."
If you are a collector you can get a cartridge and play it the way it was meant to be played: on an Atari, with a joystick, in front of a TV (preferably an old one).
If you're a casual player you can play it on just about any PC. Many people prefer playing Atari 2600 the games on the Stella emulator because it's easy, convenient, the emulation is indistinguishable from the real thing, and the picture and sound are perfectly crystal clear.
If you are a developer or just interested in programming, the game comes with all the source code and art on the CD, everything you need to build your own copy of the game (you have to download the free compiler, but the link is on the CD). You can look it over if you are just curious, or you can modify it and make it your own. The game comes with Stella which includes a full Atari 2600 graphical debugger that allows you to step through each instruction, line, or frame of the game and graphically shows all of the registers in real-time.
This may be the only chance you have to get Star Castle 2600, after this Kickstarter campaign there are no plans to produce or make available any additional cartridges, CD's, or materials.