I created an itch.io account just to tell you how I much enjoyed this game. I play Expert on Guitar Hero and SS Ruth still took me several tries, even with Glass. Just had to "get good" and I did! Got the full game SS.
I really like how you can create some pretty hard challenges for yourself depending on what cards you take in Endurance Mode. Doom+only Rituals is pretty interesting. So is Double+Fission and stacking Tempo can get crazy. Ghost+Fission or Mines is just about impossible though. The music is good as well.
The card system and Endurance Mode adds replayability. The fast travel and save code system is a nice quality of life feature. I'm sure some players would like a save file system that writes to the game (or cookies for the browser version) but this save file system works for me as I want to play in browser and I block cookies.
The platforming and the Haunted Hall and Boba minigames were a welcome surprise. Haunted Hall could probably be a game in itself with more levels and other additions. There is a typo in Tonn's dialogue "Try Hauted Hall"
Some things I would like to see in the game, (maybe after full game SS or Endurance modes beaten) an autoplay mode (to enjoy the art to the beat, like Cock Hero. The art is really good by the way,) also the ability to select which cards can show up, and/or a preselect menu to manually select what power-ups happen at what point in the song so the player doesn't need to keep re-rolling. (For before post-game, the reroll mechanic is good though.) That one would have to be after full game SS for game balancing purposes. I also would love to try an all Ritual challenge with being able to manually limit the randomized effects. (Mainly looking for an all negative effects challenge.) I noticed that cards only appear once you beat the song the cards first show up from, is Ritual limited in same way to cards that have been unlocked? I'm also hoping we would get some scenes with the Reaper and woman transmogs with the rest of the characters.
Another suggestion: I found the Yoni's missing parts section confusing and looked literally everywhere. (I'm not even exaggerating. I checked everything in the overworld, inside every tent, every garbage can, every cooler, every chair, and even everywhere inside Haunted Hall and the platforming section.) Now that I know where the parts actually were, it turns out I had them early on. I just never went back to Yoni because I didn't think I had them yet. I recommend having a message in the location where the parts actually are. Something like, "you find some unusual parts." Maybe also show them in an inventory and/or if you picked them up before Yoni asks you, you could respond with something and just hand them to her.
This is one of the most fun rhythm games I've played. Almost as good as some of the major titles out there. Who did the artwork and where can I find more? Are all of the characters created by the same person? Do they have other things out of game? Is there somewhere to go for more comics? A credits section on the main menu answering these questions and whoever did the music (edit: Wishful Simping, I just went to your Youtube Channel, which I only knew about from this comments section, you should also add that in the credits.) would be good.