Good, but could be much better.
As previous reviews have stated, this game is a blast, but it's also absolutely pointless (I know all games are, pretty much) in the way that it has no objective other than going higher. And the randomness of the zappers can make it really tricky even at 50mt high, when you could also have a very easy ride up 150mt, which is sort of unfair.
Also, the speeding up function is broken. It's more of a burden than a benefit, you end up running into zappers you didn't even know were there...
I feel this game could be downright amazing, with a few minor tweaks.
And, protip! Use w and up arrow, w on the left wall and up on the right, it feels much more natural. :D