Very good, just a few minor problems keeping it away from 5 stars:

1-it's a bit annoying that enemies can take sharp turns all of a sudden like that, it would be a better idea to have them curve more naturally instead of practivally making a 180 turn by surprise.

2-the fact that I can't move while anemy is causing damage, it means that you need to wait until they go away before moving, specially in the later levels a second enemy can take the first one's place os just bump into one of them wiht bad luck can deplete most or all of your helth very quickly.

3-The bar that shows how long power ups last should also be there for adrenaline