The game is based on the TV series by the same name which starred Jack Mullaney and Frank Aletter as astronauts, who after breaking the speed of light, accidently travel back in time to prehistoric Earth. Unable to return, they make friends with the "natives" played by Imogene Coca as "Shadd" and Joe E. Ross ("OOH, OOH" - Officer Tooty from 'Car 54, Where Are You?' fame) as "Gronk".
Halfway through the one-season run, the plot was reversed in an attempt to bolster the show's ratings. The two astronauts, who had traveled back in time, now found a way to return to 1966 and took the stone-age family with them - so the rest of the run played out with Gronk, Shadd, et al trying to adjust to life in 1966-era NYC.
This is a simple roll and move game similar to many of the times.