Cool idea. Highlight was launching a Fire Truck into the air and having it explode when it landed. I got to about 10K score :)
Theme: Explosive flying fish are cool and all, I'm just not sure I would consider the fish to be a weapon.
Creativity: Interesting concept, a creative mechanic of launching an explosive and allowing air control/momentum.
Technical Achievement: You've done well to make this work in only a 48hr jam - physics are not easy.
Polish: A few things could be tidied up, there was a bug when the camera would become inverted. I would also love the option to reset the game and go again without having to refresh the browser. I could not get the credits option on the main menu to work.
Entertainment: Fun. Liked flying over buildings and looking for my next target. I got to about 10K score.
Bonus Points: I'm not sure how to score this category - your game loaded well and ran well and was easy to fire up and play.