I got really good at making music from my Game Boy Hero games, and I still have probably 30 songs I want to add to Game Boy Hero II. And I think the endless runner concept worked amazingly well given it is a Game Boy game. Sadly its a bit too much for the DMG to handle so I had to make it a GBC game, but it was all designed to be played on the DMG. But the animations is where I spent the bulk of my development time, it became a lot of fun to experiment with how far I could push the Game Boy, and where its limits truly are. I can tell you that the rom plays flawlessly on my Analogue Pocket.
The cool thing is, I think taking what I learned about large scale animation from this game, and creating a simplified Game Boy version of an endless runner, I think I can probably make a very legitimate Temple Run port for the GBC, and I plan on doing so in the not too distant future.