I remember that game like the devil. I was about 8-10yo and me and my sister used to obsess about that game. We played it so much. I remember we always used to reach the red castle with a few lives left.
Until we soon died after hours of heavy gaming. I still remember that dreaded song.
When you finished your (FEW) lives in Alex Kidd it was GAME OVER friend. You had to start all over again. Old school japanese difficulty there.
You can't imagine the amount of crying i did back then thanks to Alex Kidd.