I really like the concept. I think it has a lot of potential.
A sound and graphic effect when the brick hits you would be helpful.
The first time I played I got stuck and couldn't jump up because the walls were too high, and I got frustrated because I didn't know how to restart; the second time I got to the very top and there was nothing else to do—I restarted again. The third time I realized you can die if you get hit by too many bricks. After that I collected a few coins until I was trapped by high walls, then I just hid under a ledge and got super high survival score by leaving the game to brush my teeth.
I think there needs to be something that happens at the top, for when you are doing well, and also for when you are trapped at the bottom.
I think it would be good if there was lava slowly rising and you lose if it hits you. Also, you can keep climbing higher and higher into the next screens if you are doing well.
Overall I think it is a great idea, and the prototype works really well.