You should add the browser message icon to you start post to show everyone that this game is playable without installation, which may increase your views.
The game feels very raw. The color changing is done in a good way, imho (tunneling block while rolling a new color). My major issue with this game was, that sometimes i had five blocks in a horiziontal row (not excatly, but overlapping), which causes an impossible situation and instant death. Feels unfair.
You could solve this by adding a simple translation to the player, when changing tracks. Something like this:
trackPosition = trackDistance * trackNumber; // trackNumber between 0 and 4
playerTargetPosition += (trackPosition - playerTargetPosition)/10;
playerPosition += (playerTargetPosition - playerPosition)/10;
Which should result in a curve like this:
![](http://i.imgur.com/cByPivH.gif)
This would make avoiding overlapping horizontal rows still hard, but not impossible.
Additionally, you should show the collision some seconds before showing the game over screen.