LogFAQs > #976931249

If I remember correctly, the original G'nG was released to arcades within a week or two of Super Mario Bros. hitting the Famicom. It's interesting to think that they were under production at the same time.

https://gamefaqs.gamespot.com/a/user_image/2/9/4/AAdlC_AAE_Ke.jpg

Both have a short, fur-faced hero rescuing a beautiful princess from a fire-spitting monster. And when you get to Ghouls 'n Ghosts, tell me this rock turtle isn't a Koopa:

https://gamefaqs.gamespot.com/a/user_image/2/9/5/AAdlC_AAE_Kf.png

It's interesting to think that Super Mario Bros. receives credit for essentially inventing the side scroller. (Even though the first two Pitfall games came first.) It makes me wonder how the history books might have been different had Ghosts 'n Goblins been released first. Super Mario Bros. would have always overtaken it for popularity. But it's interesting how close Capcom were to having the "first" major side scroller.