I feel obligated to inform people every time this happens but if you're looking to try out the GBA Gradius games, please try checking out the JP version, Gradius Generation. It adds in a bunch of unlockable challenge modes that aren't in the American release, and being a shmup, there is pretty much no language barrier to deal with.

As for the game itself, it's good, even as someone who's not much of a Gradius fan. The level design and bosses are super creative and are designed around the GBA incredibly well, and the difficulty was tough but fair.