Ok, when I hit the first guy with the umbrella, I nearly LOLed!
It's a fun concept! I think it desperately needs a score counter to add a sense of progression or goal. The attack is silly fun, but I kind of wish it was a button instead of turning left and right. That does add a level of timing/strategy, but I can't say it felt great. I liked the rain SFX. The hit SFX worked, but could be more intense to add a real feeling of impact. Not sure if you are going for a comedy angle or not, but maybe the guys flying away could let out a scream that fades as they fly off?
Last nitpick, I promise... I noticed white fringing around the sprite and some of the BG buildings. Cleaning that up would make it look more crisp and stylized.
I saw in your write up that this is your first game! Please don't take my comments above too harshly, this is quite good for a first effort. Keep at it and I expect you'll be making great things soon!