It's a decent arcade game. But the gameplay could be a little more enjoyable. Here's what I can think of:
1. When changing direction, the character's speed changes instantly, making it difficult to control.
2. It's a matter of taste, but I think if the coins were attracted to the character when zoomed in closely (say, 2-3 pixels), the game would be more enjoyable. It wouldn't make things much easier due to the fast enemies, but it would make the environment more responsive.