The arcade version of Galaga has a kill screen on Stage 256. What happens when you reach this stage depends on the difficulty setting of the game. On easy, the game resets. On hard, the words "Stage 0" stay on the screen forever. On the hardest skill, the game plays just like stage 1. However on the medium skill, the player is presented with what we see here: A cross between the 2nd challenging stage and a regular level where the enemies shoot.
I used MAME to warp to level 256 and recorded myself playing the level twice. The first time through I play as I would, the second time I don't shoot at all to show how it looks that way.