It's simple and cool.
Tips that I think that can improve:
I suffer with some bugs in the firefox, like the guy falling a little inside the ground, so when jump he just don't jump, needing to jump twice what make me die a fill times, you can make when he lands its teleports to a Y that is safe to jump, when I Win the game I don't see the end screen, because the Space jumps the end Screen, you can put a timer that make the Space don't work for 1 second. Put Space to initiate the game, so the player can repeat the loop faster. Maybe a Reward for the rocket that the player kicks that don't are in the range of the helicopter, like a wall that force player to jump, and the low rockets break it.