You have to use Octo for this jam. http://johnearnest.github.io/Octo/
What are you meaning?
This jam is about making games using Octo. That is the most important part of the jam.
Well, technically, the jam is about making CHIP-8, SCHIP or XO-CHIP games. The tooling is unrestricted, but the end result should conform to one of those three (and thus run in Octo) ;)
