[JoshM33k]

It would be interesting for the author to get a flashcart, load his rom on it, and add some video of it playing on physical GBA hardware. Then you can really find out if any quirks of the system would prevent it from running, or add any slowdown.

[mkarr]

One of the easiest ways to get code running on the GBA is via the multiboot protocol over the link port. This was the primary way I ran code on the GBA circa 2003ish using a link cable spliced into a parallel port plug.

Unfortunately, parallel ports are exceedingly uncommon these days. However, it looks like this can be done easyly enough using something like a Teensy [0] or Arduino [1].

[0] https://github.com/tangrs/usb-gba-multiboot

[1] http://web.archive.org/web/20100815071014/http://blog.evildr...

[JoshM33k]

Oh, interesting! For those of you not versed in the intricacies of playground GBA link cable gaming, this protocol was used to link multiple GBAs, where one would have a cartridge and the others would not, and they would receive the game over the link cable. These single-cart multiplayer experiences were almost always very rudimentary, because as Torgo says, you're loading the entire payload in memory.

[Torgo]

Definitely works, although you are limited to a very small payload that must be loaded completely into memory.

[gelstudios]

Apparently most bootleg GBA cartridges (usually Pokemon titles) ship with the "write enable" pin connected, so they can be re-flashed. I haven't done it myself though.