I don't have a joystick but it shouldn't be hard to make it joystick-compatible at all. :3
As far as scores go, my highest is 79k (added a video in the game page), highest on stream i've seen was 15k, highest off stream from a non-developer 38k.
Score gained per match does increase over time:
Difficulty scales over 3 minutes, reducing time gained per match (from 8s to 2s) and increasing score gain (from 1x to 3x).
Then there's also a second bonus based on the number of shapes matched which scales slowly but infinitely (linearly).
I got to 79k in about 12 mins 40s, you can see the footage in the game page (it's the video linked). :)