Shinespark stuff is some of the most rewarding, but also most frustrating aspects of 100%ing any Metroid game. I know if I didn't have save states, I'd have given up before finishing them. There's at least one in Zero Mission that was a bitch to get (in the final area of the game) that involves shinesparking up multiple levels, multiple rooms, a falling section, and a button press at the exact right time, but it felt so good to actually get it done.