I created a DDR in my game as well lmao, nice to see more people take this chance! I find it interesting that it's made in HTML+JS, did not expect to see this combination.
Can't quite tell how good the charting is because the indicators aren't very clear on when I need to press and the cursor sucks ass. Most of the time I have no idea how I'm missing notes because it feels like I should hit them and I'm doing nothing different from the nots I'm hitting, but it's just not hitting. I feel like the timing is a little too strict and the timing window a little too forward. The charting might be a tad off as well in places.
The idea is very good tho! I'd love to see this cleaned up with a better UI and indications, and I think this would be an extremely fun rhythm game! Would love to try it out again after ^^