Wow I found that stressful! The game is great!
I feel like it might have been nice to easy in a bit slower, since I did struggle a bit, but I think by the end I got a decent idea. It does sometimes feel like luck especially with the enemies just going whatever direction they please - there were occasions where I'd be basically surrounded, or it would be a guess whether the enemy decided to move or not. And I also found that It was often beneficial to try to get them to overlap, since they would take up less space that way.
The only other thing I might suggest is starting the game on the first player input, so the player can get a quick breath between goes.
Good job!