Hi @UndertakerofSouls, sorry we missed your first post. Since no one has run this category yet, the rules haven't really been properly defined, so the runners are deciding on exact rules now (the rules listed under the category were put there a long time ago by mods who aren't really active in the community right now and as you can see they are way too vague). If you would like to discuss the rules with this game's runners, I'd suggest joining the Mario Tennis series discord, which is linked in a sticky forum thread. Again sorry about missing your initial post!
(god this is super late) I submitted a run recently (I ran it March 1st it was just a pain in the ass to save convert and all that) with the rules set in place, and this is what I took out of the guidelines -- do EVERYTHING.
As in, get all the 1-Up Mushrooms. Clear all the Singles and Doubles tournaments. Do all the training courts. Do the training rooms, Power Shot and otherwise. Collect all the Power Shots.
I might have possibly overshot the landing but I figured, if you get literally everything, that's all you need. You shouldn't need to get both characters to Lv. 100 (if I can compare to the Mario Golf GBA game there) but the rest of those should apply. Feel free to correct me if I'm wrong, mods, I kinda just winged it.
EDIT: Not even gonna lie, my run isn't even /good/, I just wanted to do something besides Kid Icarus: Uprising lol
EDIT2: To answer the OP, you'd need to hit 10 in every category. The Volcano Shot needs L10 Jump, Muscle, Balance, and Body, the Shooting Star Save needs L10 Response (as well as Jump), and the Rainbow Save needs L10 Speed, ESP, and Spin. Those 3 Power Shots collectively hit all 8 categories for L10
I post here my question, just to be sure about the answer : Concerning the training for the powers (PS Speed, PS Muscle, etc...), are we forced to do all the levels of every machine (lvl 3 and challenge included) or we just have the lvl 10 in every category?
And... How is possible to beat the lvl 3 of the machine "PS Response"? It's not human ^^', have you a trick for that lvl or something like that?
PS Response is mainly just banking on a streak of the same symbol and praying it goes on for as long as possible. If anything Lv. 3 Body is a mess, HECK TACKLEBOT MAN lmao. If only more games were like the ESP game.
I'd say do all 3 levels plus challenge in each just to truly 100% but that's me, I'll leave that part up to a mod.