Does Satan's Hollow have an ending?

Satan's Hollow is a 1982 shooter arcade game from Bally Midway. The player uses a moveable gun at the bottom of the screen to shoot gargoyles flying around the top of the screen. The gun is also used to gradually build a bridge and thereby advance to the next level.

After completing each level, a white pennant is placed on a stack on the side of castle in the background:

There is room for only nine white pennants, so after earning the tenth white pennant, all the white pennants disappear and a red pennant is placed on a stack on the top of the castle. The game then continues as before, with a white pennant being awarded at the end of each level:

Judging from the size of the white stack, it looks like there is room for only six red pennants. I've played the game for a long time but have never been able to amass six red pennants. What happens when you win the seventh red pennant? Does the game end, or do you start a new stack of pennants of a different colour?

Does the game, in fact, have any ending at all, or do the levels continue indefinitely?