RosenkreuzStilette is an action platforming doujin game that was developed by independent Japanese studio [erka:es]. The gameplay takes heavy inspiration from the classic NES Mega Man games, and the art style is evocative of the IGA-era Castlevania games and early Type Moon games such as Tsukihime and Fate/stay night. It also has a generally rich plot with a good amount of worldbuilding for a doujin game.
Taking place in a medieval fantasy setting, the game revolves around the Magi, magic users who were persecuted for practicing magic. The Magi fought the Holy Empire for their freedom and rights and eventually won, finding their place as a branch of the empire's military called Rosenkreuzstilette, or RKS for short. Tensions remained, however, which led to one of their commanders, Count Michael, ordering a brutal strike against Holy Empire out of fear for his fellow Magi. Spiritia, who was away at the time, returns to find the rebellion in action and the Count's daughter Iris suddenly being whisked away by the dragon Talos, supposedly on the orders of the Count himself. Spiritia, with the help of her friends, must now rescue Iris and quell the rebellion before things get even worse.
Hetfield90 improves on their previous "Spiritia" run by about 83 seconds thanks to heavy usage of a new zipping technique and better RNG manipulation. For more details, you can read the author's notes.
For more action, there is also a run that uses Grolla by the same author.