I bought and played the physical and digital versions of this game. And it really is a good game. The music and visuals have a high level of polish. The story, despite being short, lends itself well to a pick-up-and-play style that suits the Gameboy.  

However both physical and digital versions still have the "99 Gold" bug. This bug breaks the game by making it too easy and therefore making the experience short and unfulfilling.  

If the bug gets fixed, I'll change my review to five stars. It's rare to get a modern Gameboy game with this kind of production.