For the Frog the Bell Tolls (JP) is a Game Boy video game released in 1992 exclusively in Japan. The game name is based on the novel "For Whom the Bell Tolls" by Ernest Hemingway. The game features a typical save the princess story, though it's interesting because you're trying to save the princess before your rival kingdom does. The one who saves the princess is expected to be the more favorable one among the kingdom where the princess hails.
The game has drawn comparisons with The Legend of Zelda: Link's Awakening on the Game Boy. It is seen from a birds' eye perspective and is an action-adventure game with role-playing elements thrown in there as well. Some portions of the game are sidescrollers, but only the parts that take place in castles and caves. There are parts where you transform into a frog. Though statistics are altered when you're a frog, you have enhanced jumps though worse attacks. When you transform into snake, you'll be able to crawl through small crevices.
The combat in the game is unique and very different from other role-playing games. A battle will start once the character runs into an enemy character. Following this, the player will not actually decide what the character does or what attacks he'll use, but rather he'll automatically start to attack the enemy and vice versa. Battles are won if the player has equipped his character with valuable weapons and armor, and has good statistics and health. Enemies who are incomparable to the player character in terms of statistics will run from battle and ultimately inevitable defeat.
Kazumi Totaka is credited as the game's composer. In each of his games that he's credited as a composer, he usually includes a song in the game that is extremely hard to initiate. This is one of the song's earliest appearances. You can execute the song by going into a building that automatically appears after you return to one of the villages (the third one you visit) after you exit the castle. Once inside the new building, wait for a few minutes and the song will automatically start to play.