Don't you think touhou is FAKKEN BADASS? I think this is overlooked.
First windows game came in this red cover with this girl with weirdly shaped wings, which you don't see for most of the game. You progress shooting down wildlife, and approach the mansion. Game is hard as fuck, so not many people seen it all the way through. You encounter a witch that summons fire storms on your ass, maid that summons knife storms and can stop time too, and if you've been doing well, you get to meet the mistress of the mansion and the root of all issues, the foreign vampire girl, Remilia Scarlett, which you fight with giant red moon in the background as she summons... red... balls... in your direction, which are sometimes portrayed as chains and a giant red spear. And if you did all that in one coin, you get to meet the extra boss, Devil's Little Sister, Flandre Scarlett, to whoop your ass one last time.
In the first PC-98 game, you play as a priest girl descending down into either Jigoku(Underground Jail/Hell) or Makai(World of demons/of magic) to exorcise the weirdest creatures ever seen, with one of them being a six winged angel of death.
In the fifth PC-98 game, in the end you fight the creator of all Makai and everyone in it, Shiki. Her final spellcard is her spraying bullets in almost every direction, you have to hug the wall of bullets to survive it.
Marisa's iconic move she stole either from Yuuka or Goku, Master Spark, is a giant lazer that covers most of the screen.
You get to fight a Hell-bird shooting miniature SUNS at you in the middle of lava covered old hell. You get to fight immortals. You get to fight ghosts in the middle of their reincarnation. Lightning fast swordsmen. People who can drive people insane just by looking them in the eyes. And every stage 5 boss is portrayed to be equal in strength to your character, while final boss is stronger.
Does ZUN keep it up in later games? Also post BADASS games in general. Like, dunno, Hellsinker, for having an incredibly badass name and having one of characters survive such hell all on his own for years. Or Noita, because you actually can go on and explore hell there. Or Super Spy Hunter, because great music and cool bosses I guess. Or Warning Forever, for having your enemies being 99 times bigger than you.