It's really hard. I think some improvements to the controls would make this game handle a lot better. I don't see a reason for you to ever need to split your herd, so I don't think selecting them is necessary. If you want it to be, maybe add some events to the map like buttons that you have to get a certain number of squids onto.
I also think the squid walking pathfinding could be improved if you used boids (https://en.wikipedia.org/wiki/Boids). Like how starling murmurations work.
I do like the art. Cute and simple sprites. Nice!