These aliens... they look a little bit like innocent forest animals to me. I mean, the squid was totally an alien, but the others I'm not so sure about!
A short, fun experience! This game is actually nearly playable with a controller, it just needs something bound to Attack.
I really liked the thunder and lightning effects and the general idea of an umbrella ninja who has a lethal allergy to rain. :D
Movement was very smooth, attacks were less so. I generally only knew that combat was going my way when the enemies died. I liked and appreciated the health pickups hidden around the area.
I'm not sure what advantage there is to changing the facing direction using the mouse. Since I needed both hands on the keyboard to properly move and attack at the same time it wasn't really an option in any case. It was surprising that the camera is locked into a single position, but it actually worked completely fine in this case. (My entry last year had a controllable camera but it made a lot of people sick, so your game is much better in that respect.)