Hey! You are right indeed, that's like in Zelda: Link's Awakening, now that you talk about it I remember. Maybe this idea came from there too ^^.
And you found the secret passage the way I was imagining the player finding it :) cool! Although I wanted to add some hints, the more you die the more the entrance would be obvious, so that you can be surprised to find all these magic orbs that you lost when you died :).