Aside from the epic may mays, my only experience with these games were the OST and the fangames like the recent Artificial Dream in Arcadia. Are the main SHMUP games actually worth it or not? None of the people I asked over the years knew either, funnily enough. Must have been posers or tourists.
Oh, I would also ask for a guide of some kind, preferably in image format, there is now way to just get into these games now with so many out. It would be good to know the best ones for beginners, if there is some sort of continuity with the story, which emulators to play the older ones that came out on Japanese computers on, ect.