Got to wave 8.
I think it scales quite well, and it starts getting quite hectic. The sharks however where a little bit of none-issue as i just made them get to the same corner and change the direction of them when they get back to the screen again. Sometimes the crabs stop when i click them, sometimes they start walking again before the seagull picks it up but that COULD be intentional and makes it a little more micro-manage-y. Cool way to interpret the theme, and very enjoyable. It's got a few kinks and the crabs could probably have a hitbox that is a bit nicer to the player, but all in all a good entry. Good luck!