Sinbad Nanatsu no Bouken

The premise is very simple, you have to defeat a certain amount of big bandits so their leader will appear, defeating him leaves a key which completes the stage. Level design repeats itself after seven rounds while increasing difficulty, and by the way, you can also jump onto the bandits and count that as a legit kill. Very useful in case you are surrounded by some of them and want to preserve lives. As it's an arcade-style title, the game does not end so after playing through two full loops I get a Game Over on purpose.

00:00 - Start
00:10 - First loop
07:44 - Second loop
15:01 - Game over