I've mentioned this game in the Evercade section and in the Loser section, talking about how I've never finished it and wanted it to come out on in some sort of rerelease or compilation, the Nintendo Gods heard me!
It's one of the NES games you can play on the Switch with their online service. From memory I was able to find all Indra's treasures except for the coat of arms. I did use a map twice, once to find Lapis (where the coat of arms was) and I just couldn't remember where the floating castle was.
I bet the game in one sitting. As a kid in the 80s I couldn't beat Ligar, the final boss. I assumed it was impossible and never tried the game again. Earlier this week I finally got my win, turns out the game is fairly easy.