There are no prizes awarded in the Octojam, just the warm fuzzy feeling of having finished a project, and the opportunity to have your game played and constructively critiqued in our annual post-jam stream.
Programs submitted to the jam should be compatible with CHIP-8, SCHIP, and/or XO-CHIP, and should run in Octo (with appropriate compatibility flags selected). Silicon8's additional color planes are not strictly legal. Timendus' game last year was designed such that it could be used in either Silicon8 or (degrading gracefully) in a stock XO-CHIP interpreter, which I viewed as somewhat bending the rules but not breaking them.
In the spirit of keeping everyone on a level playing field this year, I ask that participants refrain from using any custom extensions for jam submissions, as using such extensions disadvantages those who do not have the skills or desire to make their own interpreters/tooling, and makes it harder to fairly compare submissions to one another.
If participants wish to separately explore an "enhanced edition" of their programs elsewhere they are, of course, free to do so.