Rastan for the Sega master system.
I was unlucky enough to not own any video games at the time but weirdly lucky enough to have a babysitter whose son had one of the only master systems I have yet to this day seen in real life. This was the midwest United states, early 90s.
And I mean, I BEAT beat it.
If I remember correctly, if you beat the game without using any continues, you get an extra level and TRUE end boss.
Shit made my 6-7 year old self SWEAT. It's the only instance in which my child gaming self had better skills than now. I cannot recreate this feat anymore.