Congrats!! I remember it taking me 50 or 100 tries to get a good start on Hi. The difficulty with the GB version versus the NES is the GB bottle is one tile shorter and you've got no headroom to maneuver and clear out the sides.
You know the High level would be a bit easier on a regular Game Boy. The Super Game Boy speeds up the game 2-4% faster then the regular game. That is one reason the Castlevania: The Adventure, game is more playable on Super Game Boy, then the original system. But they did fix the issue for Super Game Boy 2, but that was only released in Japan.
That third ending with the coelacanth totally makes me think of the Darius games, especially the Game Boy version of Sagaia: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JI17_53t6A4.html
