 Hate my local arcade...
I've been going there for a while now, their controller never works properly. Probably because of people who think they'll get a better score if they beat it really hard.
For some time their 1P side left kat sensor was all mashed, it'd sometimes register as left kat then right kat. (So when notes like kakakat comes up, there's a high chance a malinput can break my combo)
And on my second last visit, they seemed to have fixed that problem. Actually created a different one. It doesn't pick up inputs as well as before. And on my last visit the right Don sensor was totally dead. (I was hitting the left half with both my sticks. It probably looked stupid :P)
Also they did something to the kat sensor as well, I like to sort songs by difficulty (hit both kats at the same time) but doesn't work anymore. No luck on 2P side either.
Well, at least there's no problem playing the game on 2P side. But whenever I go, I'm with someone so only one side working is no good.
The person who work there never says anything, I don't know if I can ask him to fix it again. | 
