To satisfy my ignorance I had look those up, and:

https://www.reddit.com/r/Tetris/comments/13uqby/whats_das_an...

“[…] but in general, ARR is auto repeat rate (how quickly the pieces move from right to left.) And DAS is delayed auto shift (How long you have to hold down the button to before a piece starts flying to the wall). Changing them can change how "slippery" your pieces feel and can also enable you to play a lot faster. […]”

Ah one small bug(?) I noticed was t-spins arent recognized if they're hard dropped after you spin them in. But I think this is a great showcase for reactive and it's impressive all the spins work correctly!

Thanks, I'll create an issue for it.

Here's a vid of what's possible with proper settings: https://www.youtube.com/watch?v=xUIpb-IFTZE

OMG, that video is nuts. I'm assuming that is being controlled by a human in real-time?

That's correct. With DAS tuning it's much less frustrating to play at the speed at which you can think. Here's one of the top online players of puyo puyo tetris, for reference.

https://youtu.be/7AjbWroX4vA?t=18m57s

Yep it's a human - there's a good number of people who can reach that speed but it takes years of practice. I believe a lot of the community started young on various platforms so some people have been playing 10+ years

Sure. I'll have to read up on how that stuff works, but I'm keen to make my version as playable as possible.