this year's theme: make a title screen. nice and easy, right? :)
i totally recommend giving it a shot if you're at all intrigued, especially since the goal here is a lot less ambitious than "make a game". title screens can range from very simple to as complex as you want them to be, and are a great place to show off whatever cool tricks you might figure out.
if you're used to modern game development tools, it can be a very interesting and humbling experience to program for a system with about 0.5% of the CPU clock rate and 0.0001% of the RAM you have in your big beefy desktop computer.
the GBA makes it work, though! it's this lovely middle-ground between modern and retro, being a reasonably performant 32-bit ARM with a 16-bit-era picture processing unit. if you're already handy with C, C++, Rust, or Nim, i'm willing to bet you could probably get from zero to "it draws a cute scene" in the space of a month. i believe in you!