I love this! Really great idea for the theme. The core mechanic is excellent, and while the artwork is simple, it's visually cohesive and creates a flawless visual hierarchy. I wish the game had a bit more content, but hey, there's only so much you can do in 72 hours. My only suggestion is to add a bit more juice to the bullet when you shoot the shapeshifter. Some screen shake, a strong visual effect, maybe some blood splatter, just something to give me that OOMPH! Really nice work!