I liked the music but I disliked the glitchy artstyle and like the other poster I also originally disliked the inertia, but I got used to it.
At first I disliked the enemy reaction times and how fast their bullets moved. If they see you it's game over, so I tried to approach them in a stealthy manner, THEN I started enjoying the game. Dodging the automated guns added a nice level of anxiety to spice things up.
I thought it was unbalanced to be able to kill the enemy, sometimes more than one at a time, with a single bullet from 10 miles away as in some of the levels.