People at ROMhacking.net finally finished translating For the Frog the Bell Tolls, a game about frogs and snakes and princes...
It's the precursor to The Legend of Zelda: Link's Awakening's engine for those who don't know, where Richard appears as a character in the game.
It was rather primitive, there were automatic combat scenes with the same results in which sometimes you'd need a particular item or power-up in order to win.
Another game like this was Tomato Adventure, which was an action-command RPG which was supposedly the precursor to Mario & Luigi: Superstar Saga's engine. Apparently, the Hermie III boss is actually based upon the 'Hermie' enemies in Tomato Adventure who were also decorated hermit crabs.
There's even some unused music in M&L SS based on Tomato Adventure (and possibly the canceled GBC game Gimmick Land)'s title screen.