>>3809681
Not that anon, GBStudio is incredibly limited by design as its goal of being
>A quick and easy to use drag and drop retro game creator for your favourite handheld video game system.
>drag and drop
Basically you're editing a template and then using visual scripting to flesh it out further. Visual scripting can only get you so far, and doing impressive things with the Game Boy requires you to be fluent in assembly (specifically a slightly modified Z80 assembly which is about the same as all assembly versions are to each other). Undertale isn't a complex game and it could work on the system, but this is going to be the most barebones implementation of Undertale.

Also subjectively, I think if someone were to try and port Undertale to the Game Boy (Color) they should try and take greater inspiration from how actual Game Boy (Color) RPGs looked; SaGa, the Dragon Quest ports etc., all had a specific style to its menus and they all used white backgrounds because it looked better on the hardware. Whether you design the game around four-color limitations or make the most of GBC's colors I think it should try to look like it was made for the system, rather than just ported to the system.