https://github.com/gbadev-org/awesome-gbadev has a buncha resources, though I can personally attest to Tonc as being everything you need for getting up and running (at least it was years ago when I used it, but the GBA hasn't changed since then; just the tooling and environment may have gotten better)
The BIOS, graphics, and audio firmware fit nicely with the 32bit ARM architecture such that all you have to do is poke data into the right address (usually a #define'ed pointer in C) and it DMAs to the hardware.
And unlike later consoles, there's no operating system or significant copy protection to deal with, you link in a crt0.s to put everything at the right address, load the rom into an emulator, and it will start displaying your game. When your ready, you pop a flashcart into your hardware and it will probably work too. It's all very nice.
I wasn't actually asking for anything low-code, I'm fine with coding, just hoping I can mostly stick with a C/C++ style approach without having to dig too deep into understanding the memory and registers and other things on a hardware level.
I've done some reading of materials on the hardware before (NES and GB mostly), and it's interesting, I just don't have the mental bandwidth at the moment to turn that casual understanding into usable code.
Maybe eventually I can get to that point, but for now if I can get by with mostly my game logic and some function calls to various wrappers for the hardware functionality, the better.
I'm also currently working on a new version for desktop and hopefully eventually consoles that uses 3D models, larger maps, 8 team local support, map editor, hopefully either a campaign or challenge mode (eventually, maybe not on first release), and hoping to add support for up to 150-ish stream viewers to join various teams and play on one of the 8 teams (where they vote for moves kind of like in Twitch Plays Pokemon).
Here's a year old video when I was just starting the project, I desperately need to make a newer video (hopefully this weekend finally):
But I still would love to have a weekend project at some point of making a retro version.
Either use a clever way to map your game board to 8x8 tiles, or use a large number (4/8 bit paletted color) tiles so that you can just draw arbitray images (like a bitmap, but its set up in tiles). Or just give up on trying to exactly match the hardware and just draw the hole thing using a bit map mode (e.g. mode 4, with 256 color palette and double buffering) - but that also means implementing the parallax effect by hand (since theres only one layer).
It seems like the new GBDK might be the easiest, especially since I recently ran into the source code[2] for a Wordle clone someone made using it that I could reference, but is there perhaps an even easier way? Most of the low-code software kits assume you're moving sprites around on a screen and don't seem like a good fit for the project.
[1]: https://www.newgrounds.com/portal/view/183428
[2]: https://github.com/stacksmashing/gb-wordle