I think it's a pretty decent concept! There's a lot of small things that I think would help improve the experience, such as making sure the music doesn't reset every time you go from the main menu to the manual and vice versa, or doing some spell-checking to make sure there's no unintentional grammar errors in the submission. I would also suggest making the effects of the speed card more noticeable (maybe faster), and another good thing would be to attach sound effects to the cards so that it feels good to collect them. Those are just some thoughts though; for the scope of a jam, it's hard to get everything perfect, and you showed up with a complete product at the end of the day, which is the goal!