This is definitely one of the more fun games I've played so far, the fact that your speed determines whether you'll break the white blocks is a really cool mechanic. The whole game is perfect for a game jam too, short, quick and easy to get into.
I agree with a few of the other comment that the bouncing takes you out of the action a bit, the sudden stop is a bit jarring and I found myself disappointed because I just want to go fast! Tried your updated version and it's definitely an improvement. It's a bit annoying when you die to a red brick off screen too, but don't know whether you should change that or not!
Other that that the only other suggestion I have is to show my previous best time once I complete the level (or furthest distance if you've never completed it) - just so I know what my record is to beat!
Overall, very enjoyable game though!