Hey, it looks pretty good for something so bootlegged.
The bottom corners are clearly labeled as L and R (I don't think those even do anything in-game) and the top corners are X and O, which are the buttons on Playstation pads, so I'm assuming those are the A and B Buttons on Dreamcast.
Look at all that Engrish. "Dancing Aerobic for your health!" "Now the DANCESTATION can be used for you." "The DANGESTATION [sic] is your best choice for exercise and for amusement."
Did you try it yet? How much did you pay for it? I just use my PSX dance pad since I like to use the PS2 controller on DC anyway, via PS-DC converter.