Change Direction

## Description

This game's goal is to avoid enemy by changing direction.
Your flying object flys horizontally.
Enemy is flying from front.
If your flying object collides with enemy, life will be reduced by one.
To avoid colliding, you must change direction to horizontal direction or vertical direction.
If enemy come with horizontal direction, you must change direction to vertical direction.
If enemy come with vertical direction, you must change direction to horizontal direction.
If you collect coin during game play, score will rise.
Compare your score with other's in global leaderboard.