A very fun and interesting idea! The mechanic of equipping weapons tied to a specific direction is something I've never seen before, and definitely makes deciding where to aim pretty chaotic. The fact that these weapons are also your lives is also an interesting twist.
The character designs all look very cool and good, and the sound and music aren't bad either. Very impressive!
For my taste, the field of view could be a bit larger, which would also allow for more enemies (and even more chaotic situations, I would guess).
All in all, good job!