Simple but enjoyable! The engine and wind sounds do a very good job of giving a feeling of speed. Having a different track every day is a cool idea that adds replay value, although it would also be great to have a selection of standard tracks that are always available, so you can really learn and practice over a long time period.
I think you could add some depth to the gameplay without overcomplicating it, just by adding the ability to "floor it" and accelerate extra fast. That would give players another possible action to consider when trying to beat their best time, and it comes with the built-in risk of going too fast.
Currently, I think the clicks don't don't give enough warning to be helpful. When I was playing, the clicks often started only a tenth of a second before I slid. Even if I hit the brakes with superhuman reflexes, it wouldn't be enough time to slow down. I know part of any racing game is learning the track so you can anticipate instead of reacting, but right now it feels like the clicks are just useless.
Speaking of learning the track, a great addition would be some audible scenery that you drive past. This would help make the tracks more interesting as well as assisting with memory. For example, "Okay, I can hear the church bells up ahead, I know there's a straightaway here so I can floor it. But when I hear the cows on my right, the tricky curve will be coming up soon so I need to slow down." I know there's a currently beep for each track segment, so you could learn "I need to slow down 3 seconds after the second beep", but that's not as fun or satisfying.
Anyway, nice job making a fun game in such a short time, and I hope you keep working on it!