Yes I know that guide, I have read it and it still doesn't feel pleasant to play it or freestyle.
I'm not hating the game, I like the aesthetics, I like the songs, I like everything. But playing it just feels wrong. I understand that the game is inspired by parappa but it shouldn't feel just as inconsistent with the score and grades. I'm not a game developer either, maybe it's just my fault. But throughout my playthrough I kept feeling frustrated by the game taking away my score for a line that I felt I did well and I would just like to give this feedback from someone who really likes rhythm games.
I don't know why, but it is impossible to get any other score than D or C. I never feel like I'm playing correctly no matter how well I repeat the line and when I feel like I make a perfect line I lose points. I don't know if the scoring system is poorly thought out or not intuitive. Maybe the judgement it gives to the scores is too strict but I really feel that no matter how well I keep up the pace I will not score well.
You have achieved something great
You have an audience that is very interested in this, please improve the engine and physics to make it less buggy.
You could also investigate how to make the songs loop because I feel you are using mp3 files instead of wav files so that the silent time between loops disappears.
Maybe you could make it so that the creator levels can have the camera on the back?
Although now that I think about it it would be very uncomfortable in certain levels, but it would be great to have a 3D level creator and not 2D