We had three programmers sign on before the jam. In reality, real-life had other plans. Aside from the Game jam menu and a few patches by Plide, I did the programming alone while learning the engine with almost no prior experience. The other two programmers were present for brainstorming though.
One of our early design decisions was to emulate the Sega Genesis. I took that to mean "no explicit tutorial." Funny you should mention a progression obstacle, because a training dummy was in the works --we even have the art for it-- but coding the boss took priority. Even the boss's distinct second phase got the axe due to time constraints.