This is extremely original and really cool. Plus making a networking game in the short time that a GameJam provides is a challenging decision, but it's always great to find a game that does. The lack of the tutorial makes things a bit messy, but after some playtesting it's not that hard to figure out.
I think the biggest flaw is that there seems to be no limit on the fish monstrocity you're building.
This is a great game, and one of the most original I've seen this GameJam, so congratulations to the team!