What an absolutely fun game! I am a massive fan of pixel art in general and this is some good stuff. The actual UI TV monitor is always a look I have personally loved. The actual game play is a good twist on a rhythm game.
The only issue I had with it is it feels like the bounding box/timing for the jump/S/arrow seems off. It looks like I should be able to press it maybe a pixel earlier than I actually am. I was able to make it to nearly 4000 points but the timing for the jump kept throwing me off. I think a big part of the reason for this is the character also starts to jump before I am actually able to press the key. I may try replaying again later but blocking off the top bit so it's only the scrolling button pressed.
Overall this is a great jam game and so far the one I've spent the longest playing. I was only intending to spent a few minutes on it because it seems like a fairly simple concept (Which is a good thing) to be honest. I spent over 30 minutes playing and enjoyed every second of it basically.
The only thing I would personally suggest, besides for changing the timing slightly on the jump/S/arrow, is key rebinding. Personally I would have them something like C - Coin, J - Jump, and A - Attack. Spreads out the keys a bit but then they correspond to each action.
Good job on this being your first Game Jam. :) - Deer.