Nice. I played this back in... 4th grade, was it? The speed factor in this game is really cool, and I like how you can fine-tune your runs with repeated laps of the same level. What I don't like is the needless utilization of left and right movement. This game is meant to be fast, and regardless of whether or not it helps your score, I never used the left key while playing this, nor did I ever lift up on the right key. You could have easily gotten by with a two button system for the speed burst and jumping.
Also, I noticed longer falls sometimes making me fall through the floor. Bro, what?
As far as actual gameplay goes, I feel like this game could have used more levels and just stood to be longer overall. I also didn't like that it was kind of tough to gauge how to get the best score. Yes, we see how much acorns and crowns give us. We don't see just how much MORE we benefit from getting a few extra seconds. Yes, it's nice seeing the score multiplier kicking in every second, but it's kind of cryptic and not really helpful when you're busy running your ass off.
One last annoyance was that the screens switched whenever you hit a border. This made it hard to predict just when to jump unless you memorized the course. A panning camera would not have been as stylish, but it would have made the game a lot more fair.
Overall a fun game and I love the speed, but there are several issues getting in the way of the replay value.