I very much like this game so I'll go over the good things first.
The art quality has improved compared to the last game, there are more areas and more girls which I think show how big the project has become. The background art I think is show of great improvement. The option key is working for me in this game unlike the last game. I do like that after girl has left a stall you can still recapture. I do like the animation and pose for the bathroom stalls is different to the lockers. I don't know much about how video games run but I have notice a higher qauilty.
Now the cons, though I think these are more bugs. The furthest right locker isn't working. Sometimes the game will just stop working, but will keep running. As in you can't move side to side, can't capture or see what's happening but the girls do keep on moving. I am not sure if the vending machine is suppose to work and that's what the coins are for, but it doesn't. If it's not suppose to work then I wouldn't recommend it be part of the background art. If it is suppose to work but just in a later update I think a "out of order" sign would be clear it doesn't work as of right now.
Now for things I think could be added but I understand if they don't. When girls get recaptured I think it would interesting they have a different facial expression. Expanding on that I think it would be very interesting if we have some girls searching for the monster and could have that same facial expression. I think it would also be interesting if the girls had different voice actors though I understand that probaly won't be done. I saw in the comment thread there might be teachers? Would highly recommend a different voice for that one.