This jam, like my other "Really Retro" jams, is retro themed, but with a twist (may be more than one)!
Rules (TO BE FOLLOWED STRICTLY):
1) Use a monochromatic palette (black/white, dark-green/light-green, etc.) and a pixel resolution of either 64x48 or 64x64.
2) Any game variable's information must be stored and retrieved on/from a single 64bit variable! It may be player position, score, sprites, user control data, whatever. But only on a single 64bit variable. So this means: bitwise operations will be your best friends.
2b) There are 3 exceptions to this:
> You can use auxiliary variables to temporarily move data around (as long as the data is used as its final form from said 64-bits;
> You may use constants and use their data for operations and storing onto the 64-bits.
> External things like fonts and sound can be exempted from the 64-bit variable storage restriction and may be used more freely (fonts: as long as they're for GUI/score/variable display ONLY; sound: the retro-er, the better, but ideally 1-bit sound would be nice, and a limitation of 8 sound assets could be interesting).
3) Any game engine may be used, as long as the rules of the jam are properly followed.
Good luck, everyone!!