Congratulations! You succeeded making a surprisingly fun game in quite short time. The movement mechanic was interesting and took some learning master, which made playing the game enjoyable experience.
You could include some additional variety to the game by creating different kind of obstacles (maybe even ones that move) and items that can be collected for points (or power-ups likes speed boosts, shields, ...). And if there would be an infinite mode with possibility to compete for highscore that could be the Korean part of the game. One last comment would be that I noticed there being parts of the level, where it was just possible to go straight forwards a long distance without any rocks blocking the path, which probably made the game easier.
The game was simple, yet engaging. Could have played longer if there had been more levels/content.