Whoa, you really did a lot with the visuals here! I really like the overall atmosphere. Also, the faux-3D effect is super interesting; with the parallax it really sells the effect of depth! The dialogue boxes are very clean, I liked the little mouse sprite indicating 'click to continue'.
I think the game would benefit if the controls were tightened up just a bit -- for instance, you seem to get very far from the camera very quickly, as opposed to what you might expect, where the further from the camera you get, the scaling rate slows down. Also, an autofire might be nice, although it might make the game a little too easy.
Overall, really solid, I think there is a lot to build on here! Maybe powerups and a boss fight might complete the package. Great job!