Damn, if I'd known you were making this I would have been happy to throw down a verse for the soundtrack! The instrumental is fantastic. The rapping is a mixed bag but it's not bad. There's not much art but what I do see is quite nice.
The concept is simple but not bad. The swiping makes it pretty clear this was designed with mobile in mind. The fact that the arrows go down instead of up makes me think it would have been better to have ASDF as the desktop controls. Having played DDR for years my eyes are trained to recognize arrows when they're going up, but I think anyone would be able to handle the patterns if the linear pattern represented four keys that were also laid down in a linear order. The other obvious change would be for some button that takes the next order if you're on desktop that doesn't involve swiping such as the spacebar (I lost several arrows reaching for my mouse when I saw "swipe" on the screen.)
Unfortunately the issue that I really can't get past is that the arrows are straight up broken. The timing seems to be off, but even experimenting with hitting them early or late, I found the process of hitting them to be extremely inconsistent. I'm not sure what went wrong here but a fix is definitely necessary before this is really playable.