I've been wondering something lately. If one creates a game with the controls and graphics capabilities in mind, could one transfer a game made on a home PC to a GameBoy Advance cartridge or other system pack? Is there a device capable of such a task? Is game-encoding in a cartridge more complicated than that? I'm mostly asking out of curiosity. Thanks!

No, it generally requires a complete rewrite.

Consider the vast differences in the system:

PC:
* At least one multi-GHz processor
* Several hundred MB RAM, possibly multiple GB.
* Boundless storage capacity

GBA:
* 16 MHz processor
* 1/4 MB RAM
* Extremely limited storage capacity


Many common practices on the PC today lead to serious problems on handhelds and consoles. For example, on the PC you can afford to waste a few million clock cycles on a wasteful algorithm. You can allocate and release memory and other resources as needed without worrying about fragmentation. You don't really need to worry about the size of your executable, the size of your stack, or the internal complexity of language features. On handhelds you have no such luxuries.


Then there is the radical difference between how things work. You would have to be writing your game targeting a library that works on both platforms, and I don't think there are any.



However, working the opposite direction is viable: You can write a homebrew GBA game, then modify one of the open source emulators to add a few extras on the PC.