Not bad, has nice graphics and catchy - though very repetitive - music. But I think you should have an eye on the fairness of the game, try to keep it balanced. For example, often I only saw the white lines, but had no chance of seeing which blocks are about to come after. It was purely out of luck that I hit the 5 point block instead of the 42 point block, which is a difference between minor setback and outright losing. Sometimes I even had a barrier of 25-point-blocks, although I only got like 7 points in total. That made it impossible! The chance of winning is more than often pure luck, even in easy mode, which makes the great idea, concept and graphics totally unattractive. You could try to put the blocks at the beginning of the game in a lower interval, and then increase the interval as the game continues. And when you are forced to guess which lane to take, take care that it can only set you back a bit, not totally ruin you. After all, in games it's essential to find out the correct threshold, the adequate numbers, and this can make the difference between a great game and a totally inconsisent one. Beta tester's feedback is very valuable.
The control was also hard to get. Maybe a comment like "hold the left mouse button and move your mouse to control the snake" would have been very helpful. At first I didn't even know whether to use my keyboard or my mouse! But it would have been even better if I didn't have to hold the mouse button clicked. Another nice touch would be if I could reset the game myself. It's very depressing to be at 40+ limbs, and then have to witness how I get slowly eaten by a 50+ block without any possibility to escape. And a possibility to speed things up would be nice. Maybe using the left mouse button to speed up the game would be a good idea, because it's also boring to have to witness my 50+ limb snake to bash through a 30-something block.