This is the first time a fangame has been made with the Touhou PC98s aesthetic in mind. It hits so much of the core features those games had it's insane, AND with plenty of QoL features like a proper health bar, visible hitbox, spell/nonspell practice and (probably?) a deathbomb system.
As a combo, some other core gameplay features like the actual ambientation, the patterns, story, characters and what not are all about Len'en instead. While this means this is in fact a Lenen fangame that happens to wear a PC98 skin instead of a Touhou+Len'en one, ot doesn't deter from the enjoyment in the slightest - considering I went and played many Len'en games (except BPaHC).
If you ever remotely touched any of the two you're going to have fun. Note that the game is only two full-length extra boss battles. Also with Extra and Absurd Extra difficulties. Lol