I don't often drop the 'perfect' bomb. But this game.. is so damn good!
I just got all trophies, took me about an hour or 1.5 hours. This game is perfect from head to toe, really the only thing I disliked was the enemy that shot thorns out. But like you said, it only happens when you get close to him.. Which actually I didn't know this.
Also I wanted to say, that this is the only game I have played as a flash game.. where an upgrade system was truely strategic, where any combination of upgrades can work depending on how you use them. The strategy and depth in this game is possibly the highest I have seen in a flash game.
Congrats on such a great game. Loved playing every second of it, and actually getting all the achievements!