I got really into this! The game is simple, but thanks to an impressive variety of enemies and the ability to block their shots with your own makeshift weapons makes for a tight and fun gameplay loop.
I almost made it to the end, but lost in the 3rd wave of the final level. The difficulty curve through the course of the game was good.
Although the graphics are simple, enemies and objects are clearly identifiable. Plus, you went the extra mile with little details like making your character's eyes follow your mouse! That was a nice touch.
If I had to make a suggestion, some of the sound effects could use a little tuning; some of them were much louder than others and were a little jarring at times.