This is a very unique concept and I think it could be fun with more polish. I love the aesthetics of the pixel art.
As it stands I think it's a little bit too hard and chaotic to manage all of them together. Maybe it can be fine for a later level or something but as a first level I think it feels too daunting.
I also thought at first the up/down buttons supposed to be clicked repeatedly before I find out that you can hold it down with your mouse, so I thought it could somehow be communicated better.