First, let's go through the theme hints...

"Fallout 3" was semi-jokingly called "Oblivion with Guns."

"RoadBlasters" was essentially "Outrun with Guns."

"Arkanoid" was essentially"Breakout with Guns."

B.J. Blazkowicz from the "Wolfenstein" franchise has guns.

Balrog from the "Street Fighter" franchise has guns in a different sense.

The game jam theme is...

__________ With Guns

Take something and add guns to it.  Your two weeks start now.